Automatic Transmission - Diagnosis: Pre-Check

1. Description
   • When troubleshooting OBD II vehicles, the only difference from the usual troubleshooting procedure is that you connect to the vehicle an OBD II scan tool complying with SAE J1987 or LEXUS handheld tester, and read off various data output from the vehicle's ECM.
   • OBD II regulations require that the vehicle's onboard computer lights up the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in the computer itself or in drive system components which affect vehicle emissions. In addition to the MIL lighting up when a malfunction is detected, the applicable DTCs prescribed by SAE J2012 are recorded in the ECM memory (See DIAGNOSTIC TESTS ).

     If the malfunction not occurs in 3 trips, the MIL goes off but the DTCs remain recorded in the ECM memory.

     Fig 1: Identifying Illumination Of MIL

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   • To check the DTCs, connect an OBD II scan tool or LEXUS hand-held tester to DLC3 on the vehicle. The OBD II scan tool or LEXUS hand-held tester also enables you to erase the DTCs and check freeze frame data and various forms of engine data (For instruction book).
   • DTCs include SAE controlled codes and Manufacturer controlled codes.

     SAE controlled codes must be set as prescribed by the SAE, while Manufacturer controlled codes can be set freely by the manufacturer within the prescribed limits (See DTC chart DIAGNOSTIC TROUBLE CODE CHART  ).

     Fig 2: Connecting Lexus Hand Held Tester To DLC3

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   • The diagnosis system operates in normal mode during normal vehicle use, and also has a check mode for technicians to simulate malfunction symptoms and perform troubleshooting. Most DTCs use 2 trip detection logic (*) to prevent erroneous detection. By switching the ECM to check mode when troubleshooting, the technician can cause the MIL to light up and for a malfunction that is only detected once or momentarily.

     (LEXUS hand-held tester) (See PRE-CHECK  )

   • *2 trip detection logic:

     When a logic malfunction is first detected, the malfunction is temporarily stored in the ECM memory. If the same malfunction is detected again during the 2nd test drive, this 2nd detection causes the MIL to light up.

2. Inspect the DLC3.

   The vehicle's ECM uses ISO 9141 -2 for communication.

   The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

   Fig 3: Identifying DLC3 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   DLC3 CONNECTOR TERMINALS DESCRIPTION
   
   

   Tester connection	Condition	Specified condition
   7 (Bus "(+) SLASH" Line) - 5 (Signal ground)	During communication	Pulse generation
   4 (Chassis Ground) - Body	Always	1 Ω or less
   5 (Signal Ground) - Body	Always	1 Ω or less
   16 (B+) - Body	Always	9 - 14 V

   HINT:

   If your display shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the cable of OBD II scan tool or LEXUS hand-held tester to DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side.

   • If communication is normal when the tool is connected to another vehicle, inspect DLC3 on the original vehicle.
   • If communication is still not possible when the tool is connected connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.

1. Check the MIL.
   1. The MIL comes on when the ignition switch is turned ON and the engine is not running.

      HINT:

      If the MIL does not light up, troubleshoot the combination meter (See PROBLEM SYMPTOMS TABLE under INSTRUMENT PANEL ).

   2. When the engine is started, the MIL should go off. If the lamp remains on, the diagnosis system has detected a malfunction or abnormality in the system.
   Fig 4: Identifying Malfunction Indicator Lamp (MIL)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the DTC.
   NOTE: LEXUS hand-held tester only: When the diagnostic system is switched from normal mode to check mode, it erases all DTCs and freeze frame data recorded in normal mode. So before switching modes, always check the DTCs and freeze frame data, and note them down.
   1. Prepare an OBD II scan tool (complying with SAE J1978) or LEXUS hand-held tester.
   2. Connect the OBD II scan tool or LEXUS hand-held tester to DLC3 at the lower of the instrument panel.
   3. Turn the ignition switch ON and turn the OBD II scan tool or LEXUS hand-held tester switch ON.
   4. Use the OBD II scan tool or LEXUS hand-held tester to check the DTCs and freeze frame data and note them down (For operating instructions, see the OBD II scan tool's instruction book).
   5. See DIAGNOSTIC TROUBLE CODE CHART  to confirm the details of the DTCs.
   Fig 5: Connecting OBD II Scan Tool Or Lexus Hand-Held Tester To DLC3

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE: When simulating symptoms with an OBD II scan tool (excluding LEXUS hand-held tester) to check the DTCs, use normal mode. For codes on the DTCs chart subject to "2-trip detection logic", turn the ignition switch OFF after the symptoms have been simulated the 1st time. Then repeat the simulation process again. When the program has DTCs, the DTCs are recorded in the ECM.

HINT:

LEXUS hand-held tester only: Compared to the normal mode, the check mode has high sensing ability to detect malfunctions.

Furthermore, the same diagnostic items which are detected in Normal mode can also be detected in Check mode.

1. Check the DTC.
   1. Check the initial conditions.
      • Battery positive voltage 11 V or more.
      • Throttle valve fully closed.
      • Transaxle in P position.
      • Air conditioning switched off.
   2. Turn the ignition switch OFF.
   3. Prepare a LEXUS hand-held tester.
   4. Connect the LEXUS hand-held tester to DLC3 at the lower of the instrument panel.
   5. Turn the ignition switch ON and switch the LEXUS hand-held tester ON.
      Fig 6: Connecting Lexus Hand Held Tester To DLC3

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   6. Switch the LEXUS hand-held tester from Normal mode to Check mode (Check that the MIL flashes).
   7. Start the engine (MIL goes out after the engine starts).
   8. Simulate the conditions of the malfunction described by the customer.
      NOTE: Leave the ignition switch ON until you have checked the DTCs, etc..
   9. After simulating the malfunction conditions, use the LEXUS hand-held tester diagnosis selector to check the DTCs and freeze frame data, etc..
      Fig 7: Blinking Pattern Of MIL

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      Be sure not to turn the ignition switch OFF, as turning it off switches the diagnosis system from Check mode to Normal mode, which erases all DTCs, etc.

   10. After checking the DTC, inspect the applicable circuit.
2. Clear the DTC.

   The following actions will erase the DTC and freezed frame data. Operate an OBD II scan tool (complying with SAE J1978) or LEXUS hand-held tester to erase the codes (See the OBD II scan tool's instruction book for operating instructions.).

HINT:

According to the DATA LIST displayed by the OBD II scan tool or LEXUS Hand-held tester, you can read the value of the switch, sensor, actuator and so on without parts removal. Reading the DATA LIST as a first step of troubleshooting is one of the method to shorten the labor time.

1. Warm up the engine.
2. Turn the ignition switch OFF.
3. Connect the OBD II scan tool or LEXUS Hand-held tester to the DLC3.
4. Turn the ignition switch ON.
5. According to the display on tester, read the "DATA LIST".
   Fig 8: Data List

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Performing the ACTIVE TEST using the Hand-held tester allows the relay, VSV, actuator and so on to operate without parts removal. Performing the ACTIVE TEST as a first step of troubleshooting is one of the method to shorten the labor time.

It is possible to display the DATA LIST during the ACTIVE TEST.

1. Warm up the engine.
2. Turn the ignition switch OFF.
3. Connect the LEXUS Hand-held tester to the DLC3.
4. Turn the ignition switch ON.
5. According to the display on tester, perform the "ACTIVE TEST".

Taking into consideration the results of the customer problem analysis, try to reproduce the symptoms of the trouble. If the problem is that the transmission does not up-shift, down-shift, or the shift point is too high or too low, conduct the following road test to confirm the automatic shift schedule and simulate the problem symptoms.

1. D position test

   Shift into the D position and fully depress the accelerator pedal and check the following points:

   1. Check up-shift operation.

      1 --> 2, 2 --> 3 and 3 --> O/D up-shift takes place at the shift point shown in the automatic shift schedule (See TRANSAXLE SPECIFICATIONS ).

      HINT:

      • 0/D Gear Up-shift Prohibition Control (1. Coolant temp, is 60 °C (140 °F) or less. 2. If there is a 10 km/h (6 mph) difference between the set cruise control speed and vehicle speed.)
      • O/D Gear Lock-up Prohibition Control (1. Brake pedal is depressed. 2. Coolant temp, is 60 °C (140 °F) or less.)
   2. Check for shift shock and slip.

      Check for shock and slip at the 1 --> 2, 2 --> 3 and 3 --> O/D up-shifts.

   3. Check for abnormal noises and vibration.

      Run at the D position lock-up or O/D gear and check for abnormal noises and vibration.

      HINT:

      The check for the cause of abnormal noises and vibration must be done very thoroughly as it could also be due to loss of balance in the differential torque converter clutch, etc..

   4. Check kick-down operation.

      While running in the D position, 2nd, 3rd and O/D gears, check that the possible kick-down vehicle speed limits for 2 --> 1, 3 --> 2 and O/D --> 3 kick-downs conform to those indicated on the automatic shift schedule (See TRANSAXLE SPECIFICATIONS ).

   5. Check abnormal shock and slip at kick-down.
   6. Check the lock-up mechanism.
      • Drive in D position, O/D gear, at a steady speed (lock-up ON) of about 60 km/h (37 mph).
      • Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.

      If there is a big jump in engine speed, there is no lock-up.

2. position test

   Shift into the 2 position and fully depress the accelerator pedal and check the following points:

   1. Check up-shift operation.

      Check that the 1 --> 2 up-shift takes place and that the shift point conforms to the automatic shift schedule (See TRANSAXLE SPECIFICATIONS ).

      HINT:

      There is no O/D up-shift and lock-up in the 2 position.

   2. Check engine braking.

      While running in the 2 position and 2nd gear, release the accelerator pedal and check the engine braking effect.

   3. Check for abnormal noises during acceleration and deceleration, and for shock at up-shift and down-shift.
3. L position test

   Shift into the 2 position and fully depress the accelerator pedal and check the following points:

   1. Check no up-shift.

      While running in the L position, check that there is no up-shift to 2nd gear.

   2. Check engine braking.

      While running in the L position, release the accelerator pedal and check the engine braking effect.

   3. Check for abnormal noises during acceleration and deceleration.
4. R position test

   Shift into the R position and fully depress the accelerator pedal and check for slipping.

   CAUTION: Before conducting this test ensure that the test area is free from people and obstruction.
5. P position test

   Stop the vehicle on a grade (more than 5°) and after shifting into the P position, release the parking brake. Then, check that the parking lock pawl holds the vehicle in place.

1. Check the fluid level.

   HINT:

   • Drive the vehicle so that the engine and transaxle are at normal operating temperature.

     Fluid temp.: 70 - 80 °C (158 - 176 °F) 

   • Only use the COOL range on the dipstick as a rough reference when the fluid is replaced or the engine does not run.
     1. Park the vehicle on a level surface and set the parking brake.
     2. With the engine idling and the brake pedal depressed, shift the shift lever into all positions from P to L position and return to P position.
     3. Pull out the dipstick and wipe it clean.
     4. Push it back fully into the pipe.
     5. Pull it out and check that the fluid level is in the HOT range.

        If the level is at the low side, add new fluid.

        Fluid type: ATF Type T-IV 

        Capacity: 3.5 liters (3.7 US qts, 3.1 Imp qts) 

        NOTE: Do not overfill.
2. Check the fluid condition.

   If the level is at the low side, add new fluid.

   Fig 9: Checking Fluid Level On Dipstick

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Replace the ATF.
   1. Remove the drain plug and drain the fluid.
   2. Reinstall the drain plug securely.
      Fig 10: Identifying Drain Plug

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. With the engine OFF, add new fluid through the oil filler pipe.

      Fluid type: ATF Type T-IV 

      Capacity: 3.5 liters (3.7 US qts, 3.1 lmp qts) 

   4. Start the engine and shift the shift lever into all positions from P to L position and then shift into P position.
   5. With the engine idling, check the fluid level. Add fluid up to the COOL level on the dipstick.
      Fig 11: Adding Transaxle Fluid

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   6. Check the fluid level at the normal operating temperature, 70 - 80 °C (158 - 176 °F), and add as necessary.
      NOTE: Do not overfill.
4. Check the fluid leaks.

   Check for leaks in the transaxle.

   If there are leaks, it is necessary to repair or replace O-rings, gasket, oil seals, plugs or other parts.

   Fig 12: Checking Fluid Level On Dipstick

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Inspect and adjust the shift lever position.

   When shifting the shift lever from the N position to other positions, check that the lever can be shifted smoothly and accurately to each position and that the position indicator is not aligned with the correct position.

   If the indicator is not aligned with the correct position, carry out the following adjustment procedures.

   1. Loosen the nut on the shift lever.
   2. Push the control shaft fully rearward.
      Fig 13: Locating Shift Lever Cable Nut

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Return the control shaft lever 2 notches to N position.
   4. Set the shift lever to N position.
   5. While holding the shift lever lightly toward the R position side, tighten the shift lever nut.

      Torque: 13 N.m (130 kgf.cm, 9 ft.lbf) 

   6. Start the engine and make sure that the vehicle moves forward when shifting the lever from the N to D position and reverses when shifting it to the R position.
      Fig 14: Identifying Shift Lever Positions

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Inspect and adjust the park/neutral position.

   Check that the engine can be started with the shift lever only in the N or P position, but not in other positions.

   If it is not as stated above, carry out the following adjustment procedures.

   1. Loosen the park/neutral position switch bolt and set the shift lever to the N position.
   2. Align the groove and neutral basic line.
   3. Hold in position and tighten the bolt.

      Torque: 5.4 N.m (55 kgf.cm, 48 in.lbf) 

      For continuity inspection of the park/neutral position switch, see DTC P0850 PARK/NEUTRAL SWITCH INPUT CIRCUIT .

7. Check the idle speed.

   Idle speed: 700 +/- 50 rpm 

   (In N position and air conditioner OFF) 

   Fig 15: Aligning Groove And Neutral Basic Line Of Park/Neutral Position Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Measure the stall speed.

   The object of this test is to check the overall performance of the transaxle and engine by measuring the stall speeds in the D and R positions.

   NOTE:

   • Do the test at normal operating fluid temperature 50 - 80 °C (122 - 176 °F).
   • Do not continuously run this test longer than 5 seconds.
   • To ensure safety, conduct this test in a wide, clear level area which provides good traction.
   • The stall test should always be carried out in pairs. One technician should observe the conditions of wheels or wheel stoppers outside the vehicle while the other is doing the test.
   1. Chock the 4 wheels.
   2. Connect an OBD II scan tool or LEXUS hand-held tester to DLC3.
   3. Fully apply the parking brake.
   4. Keep your left foot pressed firmly on the brake pedal.
   5. Start the engine.
   6. Shift into the D position. Press all the way down on the accelerator pedal with your right foot. Quickly read the stall speed at this time.

      Stall speed: 2,325 - 2,775 rpm 

      Evaluation: 

      PROBLEM - POSSIBLE CAUSE
      
      

      Problem	Possible cause
      (a) Stall speed low in D and R positions	Engine output may be insufficient Stator one-way clutch is operating properly HINT: If the value is larger or smaller than the specified value by 600 rpm or more, the torque converter could be faulty.
      (b) Stall speed high in D position	Line pressure too low Forward clutch slipping No.2 one-way clutch not operating properly O/D clutch slipping
      (c) Stall speed high in R position	Line pressure too low Direct clutch slipping 1st and reverse brake slipping O/D clutch slipping
      (d) Stall speed high in D and R positions	Line pressure too low Improper fluid level O/D one-way clutch not operating properly

2. Measure the time lag.

   When the shift lever is shifted while the engine is idling, there will be a certain time lapse or lag before the shock can be felt. This is used for checking the condition of the O/D direct clutch, forward clutch, and 1st and reverse brake.

   NOTE:

   • Do the test at normal operating fluid temperature 50 - 80 °C (122 - 176 °F)
   • Be sure to allow 1 minute interval between tests.
   • Take 3 measurements and take the average value.
   1. Connect an OBD II scan tool or LEXUS hand-held tester to DLC3.
   2. Fully apply the parking brake.
   3. Start the engine and check idle speed.

      Idle speed: 700 +/- 50 rpm (In N position and air conditioner OFF) 

   4. Shift the shift lever from N to D position. Using a stop watch, measure the time from when the lever is shifted until the shock is felt.

      In the same manner, measure the time lag for N --> R.

      Time lag: 

      N --> D Less than 1.2 seconds 

      N --> R Less than 1.5 seconds 

      Evaluation (If N --> D time or N --> R time lag is longer than specified): 

      PROBLEM - POSSIBLE CAUSE EVALUATION (IF N - D TIME OR N - R TIME LAG IS LONGER THAN SPECIFIED)
      
      

      Problem	Possible cause
      N --> D time lag is longer	Line pressure too low Forward clutch worn O/D one-way clutch not operating
      N --> R time lag is longer	Line pressure too low Direct clutch worn 1st and reverse brake worn O/D one-way clutch not operating properly

Measure the line pressure.

1. Warm up the ATF.
2. Remove the test plug on the transaxle case front left side and connect SST.

   (2WD: See COMPONENTS for the location to connect SST)

   (4WD: See COMPONENTS for the location to connect SST)

   SST 09992-00095 (09992-00231, 09992-00271)

3. Fully apply the parking brake and chock the 4 wheels.
4. Connect an OBD II scan tool or LEXUS hand-held tester to DLC3.
5. Start the engine and check idling speed.
6. Keep your left foot pressed firmly on the brake pedal and shift into D position.
7. Measure the line pressure when the engine is idling.
8. Depress the accelerator pedal all the way down. Quickly read the highest line pressure when engine speed reaches stall speed.
9. In the same manner, do the test in R position.

   Specified line pressure: 

   SPECIFIED LINE PRESSURE
   
   

   Condition	D position kPa (kgf/cm2 , psi)	R position kPa (kgf/cm2 , psi)
   Idling	372 - 412 (3.8 - 4.2,54 - 59)	672 - 742 (6.9 - 7.6, 97 - 107)
   Stall	931 - 1,031 (9.5 - 10.5, 134 - 149)	1,768 - 1,968 (18.0 - 20.1, 255 - 284)

   If the measured pressure is not up to specified value, recheck the throttle cable adjustment and retest.

   Evaluation 

   PROBLEM - POSSIBLE CAUSE
   
   

   Problem	Possible cause
   If the measured values at all position are higher	Throttle cable out of adjustment Throttle valve defective Regulator valve defective
   If the measured values at all position are lower	Throttle cable out of adjustment Throttle valve defective Regulator valve defective Oil pump defective O/D direct clutch defective
   If pressure is low in the D position only	D position circuit fluid leakage Forward clutch defective
   If pressure is low in the R position only	R position circuit fluid leakage Direct clutch defective 1st and reverse brake defective

HINT:

With this test, it can be determined whether the trouble is within the electrical circuit or is a mechanical problem in the transaxle.

1. Disconnect the solenoid wire.
2. Inspect the manual driving operation.

   Check that the shift and gear positions correspond with the table below.

   While driving, shift through the L, 2 and D positions. Check that the gear change corresponds to the shift position.

   Fig 16: Disconnecting Solenoid Wire

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   SHIFT AND GEAR POSITIONS
   
   

   Shift Position	Gear Position
   D	O/D
   2	O/D
   L	1st
   R	Reverse
   P	Pawl Lock

   HINT:

   If gear positions of the L, 2 and D are difficult to positions are difficult to distinguish, do the following read test.

   If any abnormality is found in the above test, the problem is in the transaxle itself.

3. Connect the solenoid wire.
4. Cancel out DTC (See PRE-CHECK ).