P0743
DTC P0743: Problem in Torque Converter Clutch Solenoid Valve CircuitNOTE:
^ Record all freeze data and review General Troubleshooting Information before you troubleshoot.
^ This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
1. Turn the ignition switch OFF.
2. Disconnect PCM connectors B (25P) and D (16P).
3. Turn the ignition switch ON (II).
4. Measure the voltage between PCM connector terminals D1 and B20 or B22.
Is there voltage?
YES-Repair short to power in the wire between PCM connector terminal D1 and the torque converter clutch solenoid valve.
NO-Go to step 5.
5. Turn the ignition switch OFF.
6. Measure the resistance between PCM connector terminals D1 and B20 or B22.
Is the resistance 12 - 25 Ohms?
YES-Go to step 11.
NO-Go to step 7.
7. Check for continuity between PCM connector terminal B20 and body ground, anti between B22 and body ground.
Is there continuity?
YES-Go to step 8.
NO-Repair open in the wires between PCM connector terminals B20, B22, and ground (G101, G102). Repair poor ground (G101, G102).
8. Disconnect the 2P connector from the torque converter clutch solenoid valve.
9. Check for continuity between PCM connector terminals D1 and B20 or B22.
Is there continuity?
YES-Repair short to ground in the wire between PCM connector terminal D1 and the torque converter clutch solenoid valve.
NO-Go to step 10.
10. Measure torque converter clutch solenoid valve resistance at the solenoid valve connector terminals
Is the resistance 12 - 25 Ohms?
YES-Check for an open in the wires between PCM connector terminal D1 and the torque converter clutch solenoid valve, and between the No. 1 terminal of the torque converter clutch solenoid valve connector and ground (G151).
NO-Replace the torque converter clutch solenoid valve.
11. Turn the ignition switch ON (II).
12. Measure the voltage between PCM connector terminals D5 and B20 or B22.
Is there battery voltage?
YES-Check for loose terminal fit in the PCM connector terminals D1 and D5. If necessary, substitute a known-good PCM and recheck.
NO-Check for blown No. 6 (15 A) fuse in the driver's under-dash fuse/relay box. If the fuse is OK, repair open in the wire between PCM connector terminal D5 and the driver's under-dash fuse/relay box.