Diagnostic Test
- CHECK FOR RELATED DTCS
- Using the scan tool, check for transmission DTCs.
Are Transmission solenoid, line pressure, speed sensor and/or loss of prime DTCs present?
Yes
- Refer to DIAGNOSIS AND TESTING and perform the appropriate diagnostic procedure. Perform the test for P0944-LOSS OF PRIME first, if present.
No
- Go To 2
- Using the scan tool, check for transmission DTCs.
- CHECK IF DTC IS CURRENT
- Using the scan tool, perform the Reverse Gear Clutch test. Follow the scan tool instructions.
- Increase the throttle angle, TPS degree to 30° for no more than a few seconds.CAUTION:
Do not overheat the transmission.
NOTE:Make sure to record all Event Data stored in the scan tool for future reference in this test procedure.
Did the clutch test pass, input speed remain at zero?
Yes
- Go To 3
No
- Go To 4
- CHECK EVENT DATA
- POSSIBLE INTERNAL TRANSMISSION CAUSES
- Remove the Transmission Oil Pan and Valve Body and check the following in accordance with the Service Information:
- Clutch or metal debris in the pan
- L/R clutch tower seal on the main valve body for cuts and the L/R accumulator piston and seals.
- Air check the Reverse and L/R Hydraulic Clutch circuits (in the case) for excessive air leakage.
NOTE:Both Hydraulic Clutch circuits contain a small bleed orifice and a small amount of air leakage is normal. The Reverse hydraulic clutch circuit bleed orifice connects to the OD hydraulic clutch cavity. A small amount of air leakage into the OD hydraulic clutch circuit is considered normal.
Were any problems found?
Yes
- Repair as necessary. If clutch debris is present, remove the transmission and inspect the Reverse and L/R clutches and inspect the Transmission Oil Pump and Main Regulator Valve for damage or sticking in its bore.NOTE:
If the L/R clutch has failed but no obvious cause is found (such as a cut piston seal, stuck regulator valve, low line pressure reading in the Event Data, or any other items listed above) replace the Transmission Solenoid/TRS Assembly in addition to any necessary internal repairs.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 5
- Remove the Transmission Oil Pan and Valve Body and check the following in accordance with the Service Information:
- CLUTCH TEST FAILURE
Did the clutch test fail in reverse?
Yes
- Go To 6
No
- Test complete.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- CHECK FOR BROKEN REVERSE SUN GEAR WELD
- Working through the windows in the bottom of the case, check for a broken Reverse Sun gear weld to the reaction carrier as follows:
- Hold the Transmission Output Shaft by holding the Transmission Manual Lever in the park position.
- Rotate the Input Annulus gear and drive shell, (the drum that encloses the two rearmost carriers).
- Check to see if the reaction carrier (the front-most carrier, whose outer shell is splined to the 2C clutch) is rotating faster than the drive shell is being turned.
Is the reaction carrier turning faster than the drive shell?
Yes
- Go To 7
No
- Replace the reaction carrier in accordance with the Service Information.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- Working through the windows in the bottom of the case, check for a broken Reverse Sun gear weld to the reaction carrier as follows:
- CHECK REVERSE CARRIER HUB
- Remove the Transmission in accordance with the Service Information and inspect the weld on the reverse carrier hub.
Were any problems found?
Yes
- Repair as necessary. Refer to the Service Information for proper repair procedures.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Disassemble and inspect the input clutch assembly. Check the Reverse clutch reaction plate snap ring. Check the OD and Reverse clutch seals, discs and bleed orifice (in the OD/Reverse clutch piston). Check the Reverse hub and shaft. Repair as necessary. Refer to the Service Information for proper repair procedures.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- Remove the Transmission in accordance with the Service Information and inspect the weld on the reverse carrier hub.
- CHECK FOR INTERMITTENT OPERATION
- Intermittent gear ratio DTCs can set by problems in the Input and Output Speed Sensor circuits and/or Speed Sensor Ground circuit.
- Remove the Starter Relay from the PDC.CAUTION:
Removal of the Starter Relay will prevent the vehicle from being started in gear.
WARNING:The Starter Relay must be removed. Failure to do so can result in possible serious or fatal injury.
- Install the Transmission Simulator (special tool #8333B, Simulator, Transmission).
- Check the Speed Sensor wiring and connectors for good connection, then perform a wiggle test using the Transmission Simulator (special tool #8333B, Simulator, Transmission).
Were any problems found?
Yes
- Repair as necessary.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Test complete.