Automatic Transmission

DTC P0734: Problem in 4th clutch and 4th clutch Hydraulic Circuit

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 then 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, then go to step 10.

NO - Replace the ATF, then go to step 4.

4. Measure the line pressure.

Is the line pressure within the service limits?

YES - Go to step 5.

NO - Repair the ATF pump and the regulator valve, or replace the transmission, then go to step 10.

5. Measure the 4th clutch pressure.

Is the 4th clutch pressure within the service limits?

YES - Go to step 6.

NO - Shift valves A, B, C, and D are stuck. Repair these valves and the hydraulic circuit, or replace the transmission, then go to step 10.

6. Clear the DTC with the HDS.
7. Test-drive the vehicle for several minutes under the same conditions as these indicated by the freeze data, or drive in 4th gear in D at speeds over 7 mph (12 km/h) for at least 12 seconds. Slowdown and stop the wheels.
8. Turn the ignition switch to LOCK (0), then repeat the test-drive in step 7, then go to step 9.
9. Monitor the OBD STATUS for P0734 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the result indicate FAILED?

YES - Repair the 4th clutch, or replace the transmission, then go to step 10.

NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. If the HDS indicates NOT COMPLETED, return to step 7 and recheck.

10. Test-drive the vehicle for several minutes under the same conditions as these indicated by the freeze data, or drive in 4th gear in D at speeds over 7 mph (12 km/h) for 12 seconds. Slow down and stop the wheels.
11. Turn the ignition switch to LOCK (0), then repeat the test-drive in step 10, then go to step 12.
12. Monitor the OBD STATUS for P0734 in the DTCs/Freeze Data in A/T Mode Menu for at least a pass/fail.

Does the result indicate PASSED?

YES - Troubleshooting is complete.

NO - If the HDS indicates FAILED, return to step 1 and recheck. If the HDS indicates NOT COMPLETED, return to step 10 and recheck.