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

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information (see GENERAL TROUBLESHOOTING INFORMATION ).

Warm up the engine to normal operating temperature (the radiator fan comes on).
Make sure that the transmission is filled to the proper level, and check for fluid leaks.
Drain the ATF (see step 3 on ATF REPLACEMENT ) 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 12.

NO -Replace the ATF (see step 5 on ATF REPLACEMENT ), then go to step 4.
Test stall speed in 1 (see STALL SPEED TEST ).
Does the stall speed test within service limits?

YES -Go to step 5.

NO -Shift valves A and D are stuck. Repair these valves and the hydraulic circuit, or replace the transmission, then go to step 12.
Measure the line pressure (see PRESSURE TEST ).
Is the line pressure within service limits?

YES -Go to step 6.

NO -Repair the ATF pump and the regulator valve, or replace the transmission, then go to step 12.
Measure the 1st clutch pressure (see PRESSURE TEST ).
Is the 1st clutch pressure within service limits?

YES -Go to step 7.

NO -Shift valves B and C are stuck. Repair these valves and the hydraulic circuit, or replace the transmission, then go to step 12.
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Test-drive under these conditions:
- Din 1st gear.
- Engine speed 1,000 rpm or more.
- Drive the vehicle at speeds over 7 mph (12 km/h) for at least 12 seconds.
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 12.

NO -Go to step 11.
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 10, 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 9.
Test-drive under these conditions:
- D in 1st gear.
- Engine speed 1,000 rpm or more.
- Drive the vehicle at speeds over 7 mph (12 km/h) for at least 12 seconds.
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 14.
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 13, 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 12.