DTC Troubleshooting

DTC P0734: Problem in 4th Clutch and 4th Clutch Hydraulic Circuit (4th gear incorrect ratio)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.

1. Warm up the engine to normal operating temperature (the radiator fan comes on).
2. Make sure that the transmission is filled to the proper level, and check for fluid leaks.
3. Drain the ATF through a strainer. Inspect the strainer for metal debris or excessive clutch material.
Does the strainer have metal debris or excessive clutch material?
YES - Replace the transmission.
NO - Replace the ATF, then go to step 4.

4. Measure the line pressure.
Is the line pressure within service limit?
YES - Go to step 5.
NO - Repair the ATF pump and the regulator valve, or replace the transmission.

5. Measure the 4th clutch pressure.
Is the 4th clutch pressure within the service limit?
YES - Go to step 6.
NO - Shift valves A, B, C, and D are stuck. Repair the shift valves and the hydraulic circuit, or replace the transmission.

6. Turn the ignition switch ON (II).
7. Clear the DTC with the HDS.
8. Test-drive the vehicle for several minutes under the same conditions as those indicated by the freeze data, or drive in 4th gear in the D position at speeds over 10 mph (16 km/h) for 20 seconds.
9. Monitor the OBD STATUS for P0734 in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES - Repair the 4th clutch, or replace the transmission.
NO - Intermittent failure, the system is OK at this time. If the screen indicates NOT COMPLETED, go to step 8.