Test TC-12A - Torque Converter Clutch (TCC) Solenoid/Transmission Relay Circuit (DTC 37/P0743)

CAUTION: Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.

NOTE: Test applies to vehicles equipped with automatic transmission only. For connector terminal identification, see CONNECTOR IDENTIFICATION in SELF-DIAGNOSTICS. For appropriate wiring diagram, see WIRING DIAGRAMS . Perform VERIFICATION TEST VER-1A after each repair.

NOTE: This procedure checks vehicle harness for shorts and opens between PCM and transmission control relay.

Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary. If connectors and terminals are okay, go to next step.
Remove transmission control relay. Inspect relay connector and terminals for damage. Repair connector and terminals as necessary. If connector and terminals are okay, go to next step.
Turn ignition on. Using scan tool in voltmeter mode, check voltage at terminal No. 11 on PCM White connector. If voltage is more than one volt, go to step 6). If voltage is one volt or less, go to next step.
Turn ignition off. Using an external ohmmeter, check resistance between terminal No. 11 on PCM White connector and transmission control relay output circuit on transmission control relay connector. If resistance is 40 ohms or more, perform you should perform TEST TC-12B . If resistance is less than 26 ohms, you should perform TEST TC-12C . If resistance is 26-40 ohms, go to next step.
Check resistance between engine ground and terminal No. 11 on PCM White connector. If resistance is less than 5 ohms, you should perform TEST TC-12D . If resistance is 5 ohms or more, you should perform TEST TC-12E .
Ensure ignition is off. Disconnect transmission solenoid connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary. If connector and terminals are okay, go to next step.
NOTE: Transmission control relay is turned off by PCM after 3 seconds with ignition on and engine off.
Turn ignition on. Using scan tool in voltmeter mode, check voltage at terminal No. 7 on transmission solenoid connector. If voltage is more than one volt, repair short to voltage in TCC solenoid control circuit. If voltage is one volt or less, go to next step.
Check voltage at terminal No. 1 on transmission solenoid connector. If voltage is more than one volt, repair short to ground in transmission relay output circuit. If voltage is one volt or less, replace transmission solenoid pack.