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Home >> Jeep >> 2003 >> Liberty Limited, 4WD, Part Time, 42RLE >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission Diagnostic Procedures >> System Description And Functional Operation >> Functional Operation >> Drive Learn Procedure-45/545RFE

Drive Learn Procedure-45/545RFE

Procedure To Learn A Smooth 1st Neutral To Drive Shift: 

Perform this procedure only if the complaint is for a delayed or harsh shift the first time the transmission is put into gear after the vehicle is allowed to set with the engine not running for at least 10 minutes. Use the following steps to have the TCM learn the 1st N-D UD CVI.

NOTE: The transmission oil temperature must be between 80-110°F (27-43°C).
  1. Start the engine only when the engine and ignition have been off for at least ten (10) minutes.
  2. With the vehicle at a stop and the service brake applied, record the UD CVI while performing a Neutral to Drive shift. During the shift, the UD CVI will temporarily show a different value which is the 1st N-D UD CVI. The 1st N-D UD CVI account for air entrapment in the UD clutch that may occur after the engine has been off for a period of time.
  3. Repeat steps  1 and  2 until the recorded 1st N-D UD CVI value stabilizes.
NOTE: It is important that this procedure be performed when the transmission temperature is between 80-110°F (27-43°C). If this procedure takes too long to complete fully for the allowed transmission oil temperature, the vehicle may be returned to the customer with an explanation that the shift will improve daily during normal vehicle usage. The TCM also learns at higher oil temperatures, but these values (line pressure correction values) are not available for viewing on the DRB III.

Procedure To Learn A Smooth Neutral To Drive Garage Shift: 

Perform this procedure if the complaint is for a delayed or harsh shift when the transmission is put into gear after the vehicle has had its first shift. Use the following steps to have the TCM learn the N-D UD CVI.

NOTE: The transmission oil temperature must be between 80-110°F (27-43°C) to learn the UD CVI. Additional learning occurs at temperatures as low as 0°F and as high as 200°F. This procedure may be performed at any temperature that experiences poor shift quality. Although the UD CVI may not change, shift quality should improve.
  1. Start the vehicle engine and shift to drive.
  2. Move the vehicle forward to a speed of at least 16 km/h (10 MPH) and come to a stop. This ensures no air is present in the UD hydraulic circuit.
  3. Perform repeated N-D shifts at a stop while pausing in Neutral for at least 2-3 seconds and monitor NORM N-D UD CVI volume until the value stabilizes. The value will change during the N-D shift. This is normal since the UD value is different for the N-1 shift then the normal value shown which is used for 4-3 coastdown and kick-downs. Perform repeated shifts in this temperature range until the NORM N-D UD CVI value stabilizes and the N-D shifts become smooth.
  4. This procedure may be performed at any temperature that experiences poor N-D shift quality. Although the NORM N-D UD CVI may not change, shift quality should improve.

Procedure To Learn The 1st 2-3 Shift After A Restart Or Shift To Reverse: 

Use the following steps to have the TCM learn the 1st 2-3 shift OD CVI.

NOTE: The transmission oil temperature must be above 80°F (27°C).
  1. With the vehicle engine running, select reverse gear for over 2 seconds.
  2. Shift the transmission to Drive and accelerate the vehicle from a stop at a steady 15 degree throttle opening and perform a 2-3 shift while noting the OD CVI. During the shift, a different value may appear on the screen, which is the 1st 2-3 OD CVI.
  3. Repeat steps  1 and  2 until the 1st 2-3 upshift becomes smooth and the 1st 2-3 OD CVI stabilizes.

Procedure To Learn A Smooth 2-3 And 3-4 Upshift: 

Use the following steps to have the TCM learn the OD and 4C CVI's.

NOTE: The transmission oil temperature must be above 110°F (43°C).
  1. Accelerate the vehicle from a stop at a steady 15 degree throttle opening and perform multiple 1-2, 2-3, and 3-4 upshifts. The 2nd 2-3 shift following a restart or shift to reverse will be shown during the shift as a value between the 1st 2-3 OD CVI and the normal OD CVI. Updates to the normal OD CVI will occur after the 2nd shift into 3rd gear, following a restart or shift to reverse.
  2. Repeat step  1 until the 2-3 and 3-4 shifts become smooth and the OD and 4C CVI become stable.

Procedure To Learn A Smooth 4-3 Coastdown And Part Throttle 4-3 Kickdown: 

Use the following steps to have the TCM learn the UD shift volume.

NOTE: The transmission oil temperature must be above 110°F (43°C).
  1. At a vehicle speed between 64-97 km/h (40-60 MPH), perform repeated 4-3 kickdown shifts.
  2. Repeat step  1 until the UD volume becomes somewhat stable and the shift becomes smooth.

Procedure To Learn A Smooth 1-2 Upshift and 3-2 Kickdown: 

Use the following steps to have the TCM learn the 2C shift volume.

NOTE: The transmission oil temperature must be above 110°F (43°C).
  1. With a vehicle speed below 48 km/h (30 MPH) and the transmission in 3rd gear, perform multiple 3-2 kickdowns.
  2. Repeat step  1 until the 3-2 kickdowns become smooth and the 2C CVI becomes stable.

Procedure To Learn A Smooth Manual 2-1 Pulldown Shift As Well As A Neutral To Reverse Shift: 

Use the following steps to have the TCM learn the LR volume.

NOTE: The transmission oil temperature must be above 110°F (43°C).
  1. With the vehicle speed around 40-48 km/h (25-30 MPH) in Manual 2nd, perform manual pull downs to Low or 1st gear at closed throttle.
  2. Repeat step  1 until the LR CVI becomes stable and the manual 2-1 becomes smooth.

Procedure To Learn A Smooth Neutral To Reverse Shift: 

Perform the following shifts.

NOTE: The transmission oil temperature must be above 110°F (43°C).
  1. With the vehicle at a stop, perform Neutral to Reverse shifts until the shift is smooth. An unlearned Neutral to Reverse shift may be harsh or exhibit a double bump.

If any of the shifts are still not smooth after the clutch volume stabilizes, an internal transmission problem may be present.

Procedure To Learn A Smooth 4-5 Upshift for 545RFE: 

Use the following steps to have the TCM learn the ALT 2C CVI.

NOTE: The transmission oil temperature must be above 110°F (43°C).
  1. Accelerate the vehicle through 88 km/h (55 MPH) at a steady 10-15 degree throttle opening and perform multiple 4-5 upshifts.
  2. Repeat step  1 until the 4-5 shift become smooth and the ALT 2C CVI become stable. There is a separate 2C volume used and learned for 4-5 shifts, ALT 2C CVI. It is independent of the 2C CVI learned on 3-2 kickdowns.
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