Automatic Transmission

DTC P0731: Problem in 1st Clutch and 1st Clutch Hydraulic Circuit (1st gear incorrect ratio)

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

1. Warm up the engine to normal operating temperature (the radiator fan
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, then go to step 11.

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

4. Measure the line pressure.

Is the line pressure within the service limit?

YES - Go to step 5.

NO - Repair the ATF pump and the regulator valve, or replace the transmission, then go to step 11.

5. Measure the 1st clutch pressure.

Is the 1st clutch pressure within the service limit?

YES - Go to step 6.

NO - Shift valves B and C are stuck. Repair the shift valves and the hydraulic circuit, or replace the transmission, then go to step 11.

6. Turn the ignition switch to ON (II).
7. Clear the DTC with the HDS.
8. Test-drive the vehicle in 1st gear in D at speeds over 7 mph (12 km/h) with the engine speed 1,000 rpm or higher for at least 12 seconds.
If the vehicle does not accelerate from a stop in 1st gear:
Shift to D. Firmly press the brake pedal, then press the accelerator pedal so the engine speed reaches at least 1,600 rpm for 5 seconds. Release the accelerator pedal and allow the engine speed to reach 1,000 rpm or less. Then drive the vehicle so that it shifts from 2nd to 3rd gear in D.
9. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0731 indicated?

YES - Repair the 1st clutch, or replace the transmission, then go to step 11.

NO - Go to step 10.

10. Monitor the OBD STATUS for P0731 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED?

YES - Intermittent failure, the system is OK at this time. If any other Temporary DTCs or DTCs were indicated in step 9, go to the indicated DTC's troubleshooting.

NO - If the HDS indicated FAILED, repair the 1st clutch, or replace the transmission. If the HDS indicates NOT COMPLETED, go to step 8.

11. Test-drive the vehicle in 1st gear in D at speeds over 7 mph (12 km/h) with the engine speed 1,000 rpm or higher for at least 12 seconds.
If the vehicle does not accelerate from a stop in 1st gear:
Shift to D. Firmly press the brake pedal, then press the accelerator pedal so the engine speed reaches at least 1,600 rpm for 5 seconds. Release the accelerator pedal and allow the engine speed to reach 1,000 rpm or less. Then drive the vehicle so that is shifts from 2nd to 3rd gear in D.
12. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0731 indicated?

YES - Check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the output shaft (countershaft) speed sensor and the PCM, then go to step 4.

NO - Go to step 13.

13. Monitor the OBD STATUS for P0731 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED?

YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 12, go to the indicated DTC's troubleshooting.

NO - If the HDS indicates FAILED, check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the output shaft (countershaft) speed sensor and the PCM, then go to step 4. If the HDS indicates NOT COMPLETED, go to step 11.