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Home >> Honda >> 2021 >> Pilot EX, AWD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transaxle - Testing & Troubleshooting >> Symptom Troubleshooting Index >> A/T System Symptom Troubleshooting Index (6-Speed A/T)

A/T System Symptom Troubleshooting Index (6-Speed A/T)

NOTE:

Do an all DTC check with the HDS, and troubleshoot any DTCs first before following the repair procedures listed in the index.

Symptom Probable cause(s) Notes
When you turn the vehicle to the ON mode, the A/T gear position indicator displays an improper indication, or it never displays at all
  • F-CAN communication line error
  • Gauge control module defective
  • PCM defective
A/T gear position indicator does not indicate with the shift lever in that position
  • F-CAN communication line error
  • Gauge control module defective
  • Transmission range switch defective or out of adjustment
  • PCM defective
Shift indicator does not work
  • F-CAN communication line error
  • Gauge control module defective
  • Transmission range switch defective
  • PCM defective
When you turn the vehicle to the ON mode, the D4 indicator comes on and stays on in all shift lever positions, or it never comes on at all
  • F-CAN communication line error
  • Gauge control module defective
  • D4 switch defective
  • D4 switch circuit defective
  • PCM defective
D4 indicator does not come on in D4 driving mode
  • F-CAN communication line error
  • Gauge control module defective
  • D4 switch defective
  • D4 switch circuit defective
  • PCM defective
Transmission shifts into 5th or 6th gear in D even though the D4 switch is pressed
  • D4 switch defective
  • D4 switch circuit defective
  • Transmission range switch defective
Shift lever cannot be moved from P while pressing on the brake pedal
  • Shift lock solenoid defective
  • Shift lock solenoid control circuit
  • Shift lock mechanism defective
  • Brake pedal position switch circuit
  • Brake pedal position switch defective
  • Transmission range switch ATPP switch stuck OFF
  • Transmission range switch ATPP switch line opened
  • Accelerator pedal position sensor circuit
  • Accelerator pedal position sensor defective
  • Relative throttle position sensor value too high
  • Throttle body defective
HDS does not communicate with the PCM DLC circuit error Troubleshoot the DLC circuit - Refer to: DLC Circuit Troubleshooting (2016 2017 2018), or DLC Circuit Troubleshooting (2019 2020 2021: Without CAN Gateway), or DLC Circuit Troubleshooting (2019 2020 2021: With CAN Gateway) .
Engine runs, but vehicle does not move in any gear
  • Transmission range switch broken or out of adjustment
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • Low ATF level
  • ATF pump worn or binding
  • Main regulator valve stuck or spring worn
  • Foreign material in separator plate orifice
  • Manual valve defective
  • ATF strainer clogged
  • Torque converter regulator valve defective
  • Mainshaft worn or damaged
  • Countershaft worn or damaged
  • Final gears worn or damaged
  • Park mechanism defective
  • Selector control shaft worn or damaged
  • Axle disengaged
  • Inspect the transmission range switch . If the transmission range switch fails the inspection, replace the switch. If the inspection is OK, check for proper transmission range switch installation, and adjust the shift cable.
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Replace the torque converter.
  • Check the ATF level, and check the ATF lines for leaks and loose connections. If necessary, clean the ATF lines.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Check the main regulator valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the manual valve in the manual valve body for wear and damage, and check the manual lever guide pin for wear and damage.
  • Check the ATF strainer for debris. If the strainer is clogged, find the damaged components that caused the debris. If no cause for contamination is found, replace the torque converter.
  • Check the torque converter regulator valve in the regulator valve body for free movement, and check the valve spring for wear and damage.
  • Inspect the differential pinion gears for wear. If the differential pinion gears are worn, replace the differential assembly, replace the ATF strainer, thoroughly clean the transmission, and clean the ATF lines.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Install the main seal flush with the torque converter housing. If you push it into the torque converter housing until it bottoms out, it will block the fluid return passage and result in damage.
  • Inspect the mainshaft and the countershaft for wear and damage.
  • Inspect the park mechanism at the park lever link and park gear.
  • Check the axles.
Vehicle moves in R, but not in D
  • Transmission range switch broken or out of adjustment
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Manual valve defective
  • 1st accumulator defective
  • Idler gears worn or damaged
  • Inspect the transmission range switch . If the transmission range switch fails the inspection, replace the switch. If the inspection is OK, check for proper transmission range switch installation, and adjust the shift cable.
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Check the manual valve in the manual valve body for wear and damage, and check the manual lever guide pin for wear and damage.
  • Check the 1st accumulator piston, the O-ring, and the spring in the manual valve body for wear and damage.
  • Inspect the mainshaft, the countershaft, the secondary shaft, the third shaft, and idler gears for wear and damage.
Vehicle moves in D, but not in R (or moves forward in R)
  • Transmission range switch broken or out of adjustment
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Shift fork shaft stuck
  • Manual valve defective
  • 4th accumulator defective
  • 4th clutch defective
  • Reverse gears worn or damaged
  • Reverse idler gear shaft/holder worn or damaged
  • Reverse selector or reverse selector hub worn or damaged
  • Inspect the transmission range switch . If the transmission range switch fails the inspection, replace the switch. If the inspection is OK, check for proper transmission range switch installation, and adjust the shift cable.
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Check for a missing shift fork bolt on the shift fork shaft.
  • Check the shift fork shaft detent for wear and damage.
  • Check the manual valve in the manual valve body for wear and damage, and check the manual lever guide pin for wear and damage.
  • Check the 4th accumulator piston, the O-ring, and the spring in the regulator valve body for wear and damage.
  • Check the 4th clutch pressure .
  • Inspect the clutch clearance for the 4th clutch .
  • Inspect the reverse idler gear shaft/holder for wear and damage.
  • Inspect the reverse selector gear teeth chamfers, and inspect the engagement teeth chamfers of the third shaft reverse gear and the reverse selector hub. Replace the reverse gears and the reverse selector if they are worn or damaged. If the transmission makes clicking, grinding, or whirring noises, also replace the third shaft 4th gear, the reverse idler gear, the mainshaft 3rd gear, and the countershaft 2nd gear.
Poor acceleration; engine revs up abnormally high when starting off in D and R
  • A/T clutch pressure control solenoid valve D defective
  • Output shaft (countershaft) speed sensor defective
  • Torque converter one-way clutch defective
  • Low ATF level
  • ATF pump worn or binding
  • Main regulator valve stuck or spring worn
  • ATF strainer clogged
  • Stator shaft worn or damaged
  • Inspect A/T clutch pressure control solenoid valve D with the HDS.
  • Check the output shaft (countershaft) speed sensor installation.
  • Inspect the output shaft (countershaft) speed sensor O-ring for wear and damage.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Replace the torque converter.
  • Check the ATF level. If the level is below the lower level, check the ATF lines for leaks and loose connections. If necessary, clean the ATF lines.
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Check the main regulator valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
  • Check the ATF strainer for debris. If the strainer is clogged, find the damaged components that caused the debris. If no cause for contamination is found, replace the torque converter.
  • Check the stator shaft splines for wear and damage.
Poor acceleration; engine revs up abnormally high when starting off in D and R; stall speed high in D
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • 1st accumulator defective
  • 1st clutch defective
  • 2nd clutch defective
Poor acceleration; engine revs up abnormally high when starting off in D and R; stall speed high in R
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • 4th accumulator defective
  • 4th clutch defective
Poor acceleration; engine revs up abnormally high when starting off in D and R; stall speed low
  • Engine output low
  • Torque converter clutch piston defective
Engine idle vibration
  • Engine output low
  • Torque converter clutch piston defective
  • Transmission or engine mount defective
Vehicle moves in N
  • Shift solenoid valve C defective
  • Line pressure solenoid valve A defective
  • ATF temperature sensor defective
  • Low ATF level
  • Excessive ATF
  • Main regulator valve stuck or spring worn
  • Foreign material in separator plate orifice
  • Lubrication regulator valve defective
  • Lubrication shift valve defective
  • Lock-up shift valve defective
  • 1st clutch defective
  • 2nd clutch defective
  • 3rd clutch defective
  • 4th clutch defective
  • 5th clutch defective
  • 6th clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Needle bearings seized, worn, or damaged
  • Inspect the shift solenoid valve C function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect the line pressure solenoid valve A function with the HDS.
  • Check for a seized line pressure solenoid valve A, and inspect the O-rings.
  • Check the ATF level. If the level is below the lower level, check the ATF lines for leaks and loose connections. If necessary, clean the ATF lines.
  • Check the ATF level. If the level is above the upper level, drain the ATF if it is over-filled.
  • Check the ATF temperature sensor O-ring for wear and damage.
  • Check the main regulator valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
  • Check all clutch pressures .
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the lubrication regulator valve, the lubrication shift valve, and the lock-up shift valve in the main valve body for free movement, and check the valve springs for wear and damage.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Inspect the clutch clearance for all clutches .
  • Check the needle bearings on all shafts for seizure, wear, and damage.
Delayed engagement after shifting from N to D, or excessive shock when shifting
  • Shift solenoid valve C defective
  • A/T clutch pressure control solenoid valve D defective
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • ATF temperature sensor defective
  • Low ATF level
  • Foreign material in separator plate orifice
  • 1st accumulator defective
  • ATF strainer clogged
  • Lock-up shift valve defective
  • 1st clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect the shift solenoid valve C function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve D with the HDS.
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Inspect the ATF temperature sensor O-ring for wear and damage.
  • Check the ATF level. If the level is below the lower level, check the ATF lines for leaks and loose connections. If necessary, clean the ATF lines.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Check the ATF strainer for debris. If the strainer is clogged, find the damaged components that caused the debris. If no cause for contamination is found, replace the torque converter.
  • Check the lock-up shift valve in the main valve body for free movement, and check the valve spring for wear and damage.
  • Check the 1st clutch pressure .
  • Inspect the clutch clearance for the 1st clutch .
  • Check the 1st accumulator piston, the O-ring, and the spring in the manual valve body for wear and damage.
Delayed engagement after shifting from N to R, or excessive shock when shifting
  • Shift solenoid valve C defective
  • A/T clutch pressure control solenoid valve D defective
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • ATF temperature sensor defective
  • Foreign material in separator plate orifice
  • Shift valve C defective
  • Reverse inhibitor valve defective
  • 4th accumulator defective
  • 4th/reverse air check valve stuck
  • ATF strainer clogged
  • Lock-up shift valve defective
  • 4th clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect the shift solenoid valve C function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve D with the HDS.
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Inspect the ATF temperature sensor O-ring for wear and damage.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Check the ATF strainer for debris. If the strainer is clogged, find the damaged components that caused the debris. If no cause for contamination is found, replace the torque converter.
  • Check the lock-up shift valve, shift valve C, and the reverse inhibitor valve in the main valve body for free movement, and check the valve spring for wear and damage.
  • Check the 4th clutch pressure .
  • Inspect the clutch clearance for the 4th clutch .
  • Check the 4th accumulator piston, the O-ring, and the spring in the regulator valve body for wear and damage.
  • Check for a stuck 4th/reverse air check valve in the main valve body.
Transmission does not shift
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Output shaft (countershaft) speed sensor defective
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
  • Check the output shaft (countershaft) speed sensor installation.
  • Inspect the output shaft (countershaft) speed sensor O-ring for wear and damage.
Excessive shock or engine revs up abnormally high on all upshifts and downshifts
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Input shaft (mainshaft) speed sensor defective
  • Output shaft (countershaft) speed sensor defective
  • ATF temperature sensor defective
  • Low ATF level
  • ATF pump worn or binding
  • Main regulator valve stuck or spring worn
  • Foreign material in separator plate orifice
  • 1st accumulator defective
  • ATF strainer clogged
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
  • Check the speed sensor installation.
  • Inspect the speed sensor O-ring for wear and damage.
  • Inspect the ATF temperature sensor O-ring for wear and damage.
  • Check the ATF level. If the level is below the lower level, check the ATF lines for leaks and loose connections. If necessary, clean the ATF lines.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Check the main regulator valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the 1st accumulator piston, the O-ring, and the spring in the manual valve body for wear and damage.
  • Check the ATF strainer for debris. If the strainer is clogged, find the damaged components that caused the debris. If no cause for contamination is found, replace the torque converter.
  • Inspect the clutch clearance for all clutches .
Excessive shock or engine revs up abnormally high on 1-2 upshift or 2-1 downshift
  • Shift solenoid valve A defective
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Transmission fluid pressure switch A (2nd clutch) defective
  • Foreign material in separator plate orifice
  • A/T clutch pressure control solenoid valve A accumulator defective
  • 2nd air check valve stuck
  • 2nd clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect the shift solenoid valve A function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the 2nd clutch pressure .
  • Inspect the clutch clearance for the 2nd clutch .
  • Check the A/T clutch pressure control solenoid valve A accumulator piston, the O-ring, and the springs in the secondary valve body for wear and damage.
  • Check for a stuck 2nd air check valve in the torque converter housing.
Symptom Probable cause(s) Notes
Excessive shock or engine revs up abnormally high on 2-3 upshift or 3-2 downshift
  • Shift solenoid valve A defective
  • Shift solenoid valve B defective
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Transmission fluid pressure switch B (3rd clutch) defective
  • Foreign material in separator plate orifice
  • A/T clutch pressure control solenoid valve A accumulator defective
  • A/T clutch pressure control solenoid valve B accumulator defective
  • 2nd air check valve stuck
  • 3rd air check valve stuck
  • 2nd clutch defective
  • 3rd clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect the shift solenoid valves A and B function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the 2nd and 3rd clutch pressures .
  • Inspect the clutch clearance for the 2nd and 3rd clutches .
  • Check the A/T clutch pressure control solenoid valve A and B accumulator pistons, the O-rings, and the springs in the secondary valve body for wear and damage.
  • Check for a stuck 2nd air check valve in the torque converter housing.
  • Check for a stuck 3rd air check valve in the stator shaft support.
Symptom Probable cause(s) Notes
Excessive shock or engine revs up abnormally high on 3-4 upshift or 4-3 downshift
  • Shift solenoid valve B defective
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Transmission fluid pressure switch C (4th clutch) defective
  • Shift fork shaft stuck
  • Foreign material in separator plate orifice
  • Shift valve C defective
  • Reverse inhibitor valve defective
  • D inhibitor valve defective
  • A/T clutch pressure control solenoid valve B accumulator defective
  • A/T clutch pressure control solenoid valve C accumulator defective
  • 3rd air check valve stuck
  • 4th/reverse air check valve stuck
  • 3rd clutch defective
  • 4th clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect the shift solenoid valve B function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
  • Check for a missing shift fork bolt on the shift fork shaft.
  • Check the shift fork shaft detent for wear and damage.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check shift valve C, the reverse inhibitor valve, and the D inhibitor valve in the main valve body for free movement, and check the valve spring for wear and damage.
  • Check the 3rd and 4th clutch pressures .
  • Inspect the clutch clearance for the 3rd and 4th clutches .
  • Check the A/T clutch pressure control solenoid valve B and C accumulator pistons, the O-rings, and the springs in the secondary valve body for wear and damage.
  • Check for a stuck 3rd air check valve in the stator shaft support.
  • Check for a stuck 4th/reverse air check valve in the main valve body.
Symptom Probable cause(s) Notes
Excessive shock or engine revs up abnormally high on 4-5 upshift or 5-4 downshift
  • Shift solenoid valve A defective
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Transmission fluid pressure switch D (5th clutch) defective
  • Shift fork shaft stuck
  • Foreign material in separator plate orifice
  • Shift valve C defective
  • Reverse inhibitor valve defective
  • D inhibitor valve defective
  • A/T clutch pressure control solenoid valve A accumulator defective
  • A/T clutch pressure control solenoid valve C accumulator defective
  • 4th/reverse air check valve stuck
  • 5th air check valve stuck
  • 4th clutch defective
  • 5th clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect the shift solenoid valve A function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
  • Check for a missing shift fork bolt on the shift fork shaft.
  • Check the shift fork shaft detent for wear and damage.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check shift valve C, the reverse inhibitor valve, and the D inhibitor valve in the main valve body for free movement, and check the valve spring for wear and damage.
  • Check the 4th and 5th clutch pressures .
  • Inspect the clutch clearance for the 4th and 5th clutches .
  • Check the A/T clutch pressure control solenoid valve A and C accumulator pistons, the O-rings, and the springs in the secondary valve body for wear and damage.
  • Check for a stuck 4th/reverse air check valve in the main valve body.
  • Check for a stuck 5th air check valve in the torque converter housing.
Symptom Probable cause(s) Notes
Excessive shock or engine revs up abnormally high on 5-6 upshift or 6-5 downshift
  • Shift solenoid valve A defective
  • Shift solenoid valve B defective
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Transmission fluid pressure switch E (6th clutch) defective
  • Foreign material in separator plate orifice
  • A/T clutch pressure control solenoid valve A accumulator defective
  • A/T clutch pressure control solenoid valve B accumulator defective
  • 5th air check valve stuck
  • 6th air check valve stuck
  • 5th clutch defective
  • 6th clutch defective
  • Clearance between clutch end-plate and top disc incorrect
  • Inspect the shift solenoid valves A and B function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
  • Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
  • Check the 5th and 6th clutch pressures .
  • Inspect the clutch clearance for the 5th and 6th clutches .
  • Check the A/T clutch pressure control solenoid valve A and B accumulator pistons, the O-rings, and the springs in the secondary valve body for wear and damage.
  • Check for a stuck 5th air check valve in the torque converter housing.
  • Check for a stuck 6th air check valve in the stator shaft support.
Symptom Probable cause(s) Notes
Noise from transmission in all shift lever positions
  • ATF pump worn or binding
  • Lubrication regulator valve defective
  • Lubrication shift valve defective
  • Final gears worn or damaged
  • Idler gears worn or damaged
  • Thrust washers seized, worn or damaged
  • Mainshaft, countershaft, secondary shaft, and third shaft bearings worn or damaged
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Inspect the differential pinion gears for wear. If the differential pinion gears are worn, replace the differential assembly, replace the ATF strainer, thoroughly clean the transmission, and clean the ATF lines.
  • Check the ATF strainer for debris. If the strainer is clogged, find the damaged components that caused the debris. If no cause for contamination is found, replace the torque converter.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Install the main seal flush with the torque converter housing. If you push it into the torque converter housing until it bottoms out, it will block the fluid return passage and result in damage.
  • Check the ball bearing for the mainshaft, the countershaft, the secondary shaft, and the third shaft.
  • Inspect the mainshaft, the countershaft, the secondary shaft, the third shaft, and idler gears for wear and damage.
  • Check the thrust washers on all shafts for seizure, wear, and damage.
  • Check the lubrication regulator valve and the lubrication shift valve in the main valve body for free movement, and check the valve springs for wear and damage.
Noise from transmission in D
  • A/T clutch pressure control solenoid valve A defective
  • A/T clutch pressure control solenoid valve B defective
  • A/T clutch pressure control solenoid valve C defective
  • Inspect A/T clutch pressure control solenoid valve A with the HDS.
  • Inspect A/T clutch pressure control solenoid valve B with the HDS.
  • Inspect A/T clutch pressure control solenoid valve C with the HDS.
Noise from transmission in R Reverse gears worn or damaged
  • Inspect the reverse idler gear shaft/holder for wear and damage.
  • Inspect the reverse selector gear teeth chamfers, and inspect the engagement teeth chamfers of the third shaft reverse gear and the reverse selector hub. Replace the reverse gears and the reverse selector if they are worn or damaged. If the transmission makes clicking, grinding, or whirring noises, also replace the third shaft 4th gear, the reverse idler gear, the mainshaft 3rd gear, and the countershaft 2nd gear.
Vehicle does not accelerate above 34 mph (55 km/h) Torque converter one-way clutch defective
Symptom Probable cause(s) Notes
Vibration in all shift lever positions
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • ATF pump worn or binding
  • Transmission or engine mount defective
  • Low engine output (horsepower)
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Inspect the differential pinion gears for wear. If the differential pinion gears are worn, replace the differential assembly, replace the ATF strainer, thoroughly clean the transmission, and clean the ATF lines.
  • Replace the torque converter.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Inspect the transmission or engine mount.
  • Check The Valve Adjustment .
  • Check the engine control system.
Shift lever does not operate smoothly
  • Transmission range switch defective or out of adjustment
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Manual valve defective
  • Selector control shaft worn or damaged
  • Inspect the transmission range switch. If the transmission range switch fails the inspection, replace the switch. If the inspection is OK, check for proper transmission range switch installation, and adjust the shift cable.
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Check the manual valve in the main valve body for wear and damage, and check the manual lever guide pin for wear and damage.
Transmission does not shift into P
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Park mechanism defective
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Inspect the countershaft and the secondary shaft for wear and damage.
  • Inspect the park mechanism at the parking holder and park gears.
Symptom Probable cause(s) Notes
Torque converter clutch does not disengage
  • Shift solenoid valve C defective
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • Lock-up shift valve defective
  • Inspect the shift solenoid valve C function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Replace the torque converter.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Check the lock-up shift valve in the main valve body for free movement, and check the valve springs for wear and damage.
Torque converter clutch does not operate smoothly
  • A/T clutch pressure control solenoid valve D defective
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • Torque converter regulator valve defective
  • Lock-up control valve defective
  • Inspect A/T clutch pressure control solenoid valve D with the HDS.
  • Check the line pressure .
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Replace the torque converter.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Check the torque converter regulator valve and the lock-up control valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
Symptom Probable cause(s) Notes
Torque converter clutch does not engage
  • Shift solenoid valve C defective
  • A/T clutch pressure control solenoid valve D defective
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • Torque converter regulator valve defective
  • Lock-up shift valve defective
  • Lock-up control valve defective
  • Inspect the shift solenoid valve C function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Inspect A/T clutch pressure control solenoid valve D with the HDS.
  • Check the line pressure .
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Replace the torque converter.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Check the torque converter regulator valve and the lock-up control valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
  • Check the lock-up shift valve in the main valve body for free movement, and check the valve springs for wear and damage.
A/T gear position indicator does not indicate shift lever positions
  • Transmission range switch defective or out of adjustment
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Inspect the transmission range switch. If the transmission range switch fails the inspection, replace the switch. If the inspection is OK, check for proper transmission range switch installation, and adjust the shift cable.
  • Check for a loose shift cable at the shift lever and the selector control lever.
Speedometer and odometer do not work Output shaft (countershaft) speed sensor defective
  • Check the output shaft (countershaft) speed sensor installation.
  • Inspect the output shaft (countershaft) speed sensor O-ring for wear and damage.
  • Check for a poor connection at the output shaft (countershaft) speed sensor.
Symptom Probable cause(s) Notes
Engine does not start
  • Transmission range switch defective or out of adjustment
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • ATF pump worn or binding
  • Mainshaft worn or damaged
  • Inspect the transmission range switch. If the transmission range switch fails the inspection, replace the switch. If the inspection is OK, check for proper transmission range switch installation, and adjust the shift cable.
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Replace the torque converter.
  • Inspect the mainshaft.
Engine stalls when shifted to D from N
  • Shift solenoid valve C defective
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • Torque converter regulator valve defective
  • Lock-up shift valve defective
  • Lock-up control valve defective
  • Inspect the shift solenoid valve C function with the HDS.
  • Check for a seized shift solenoid valve, and inspect the O-rings.
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Replace the torque converter.
  • Check the torque converter regulator valve and the lock-up control valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
  • Check the lock-up shift valve in the main valve body for free movement, and check the valve springs for wear and damage.
Symptom Probable cause(s) Notes
Engine stops when shifted to R from N
  • Drive plate defective or transmission incorrectly installed
  • Torque converter clutch piston defective
  • Torque converter defective
  • Torque converter regulator valve defective
  • Lock-up shift valve defective
  • Lock-up control valve defective
  • Check for an incorrectly installed transmission, and check the drive plate for wear and damage. Replace the drive plate if it is worn or damaged.
  • Check the stall speed - Refer to: Stall Speed Test(9-Speed A/T),  or Stall Speed Test(6-Speed A/T) .
  • Check the line pressure .
  • Improper alignment of the ATF pump and the torque converter housing may cause ATF pump seizure. The symptoms are mostly an rpm-related ticking noise or a high pitched squeak.
  • Be careful not to damage the torque converter housing when replacing the main ball bearing. You may also damage the ATF pump when you torque down the main valve body. This will cause ATF pump seizure, use the proper tools.
  • Replace the torque converter.
  • Check the torque converter regulator valve and the lock-up control valve in the regulator valve body for free movement, and check the valve springs for wear and damage.
  • Check the lock-up shift valve in the main valve body for free movement, and check the valve springs for wear and damage.
No engine braking
  • Shift cable broken, binding, or out of adjustment
  • Connection between shift cable and transmission or shift lever is worn
  • Output shaft (countershaft) speed sensor defective
  • Check for a loose shift cable at the shift lever and the selector control lever.
  • Check the output shaft (countershaft) speed sensor installation.
  • Inspect the output shaft (countershaft) speed sensor O-ring for wear and damage.
Engine does not rev to high rpm, and the transmission upshifts at low rpm (engine at normal operating temperature)
  • VTEC rocker arms defective
  • Low fuel pressure
  • Engine low on power