DTC Troubleshooting

DTC Troubleshooting: P0731 (64)

DTC P0731:

1st Gear Incorrect Ratio

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review the General Troubleshooting Information How to Troubleshoot the A/T System.

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, then go to step 11.

NO -

Replace the ATF, then go to step 4.

4. Start the engine in P, run the vehicle in 1st gear in S.

Does the vehicle run with 1st gear in S?

YES -

Go to step 5.

NO -

Faulty the 1st gear one-way clutch. Inspect the 1st gear one-way clutch A/T Secondary Shaft 1st Gear One-Way Clutch Inspection, then go to step 11.

5. Measure the line pressure A/T Pressure Test.

Is the line pressure within the service limits?

YES -

Go to step 6.

NO -

Repair the ATF pump and the regulator valve, or replace the transmission, then go to step 11.

6. Measure the 1st clutch pressure A/T Pressure Test.

Is the 1st clutch pressure within the service limits?

YES -

Go to step 7.

NO -

Shift valves B and C are stuck. Repair these valves and hydraulic circuit, or replace the transmission, then go to step 11.

7. Clear the DTC with the HDS.

8. Start the engine in P. With the brake pedal pressed, shift to D, and press the accelerator pedal for 5 seconds at about 3 % opened-throttle, then release the accelerator until the engine speed comes down below 1,000 rpm. Release the brake pedal, and drive the vehicle in 1st gear for at least 12 seconds, then press the accelerator pedal so that the transmission shift through all five gears. Slow down, and stop the wheels.

9. Check for Pending or Confirmed 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 Pending or Confirmed DTCs were indicated in step 9, go to the indicated DTC's troubleshooting.

NO -

If the HDS indicates FAILED, repair the 1st clutch, or replace the transmission, then go to step 11. If the HDS indicates NOT COMPLETED, go to step 8.

11. Start the engine in P. With the brake pedal pressed, shift to D, and press the accelerator pedal for 5 seconds at about 3 % opened-throttle, then release the accelerator until the engine speed comes down below 1,000 rpm. Release the brake pedal, and drive the vehicle in 1st gear for at least 12 seconds, then press the accelerator pedal so that the transmission shift through all five gears. Slow down, and stop the wheels.

12. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0731 indicated?

YES -

Check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor, the output shaft (countershaft) speed sensor, and the PCM, then go to step 1.

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 Pending or Confirmed 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 between the input shaft (mainshaft) speed sensor, the output shaft (countershaft) speed sensor, and the PCM, then go to step 5. If the HDS indicates NOT COMPLETED, go to step 11.