P0743-TCC SOLENOID CIRCUIT

For a complete wiring diagram Refer to Section 8W

Theory of Operation

The TCC Solenoid is activated when the Transmission Control Module (TCM) determines that the Torque Converter Clutch should be activated. The Torque Converter Clutch is a variable slip torque clutch that allows control of the slip from 5.5% to 95.5% of lock-up. The Clutch is controlled by the TCC Solenoid which is pulse width modulated (PWM) to provide the desired amount of slip. The clutch requires both an electrical PWM of 1000Hz and an hydraulic PWM of 100Hz.

• When Monitored:

  Continuously with the ignition on, engine running, with the transmission in gear, the TCC Solenoid is inactive, or when the TCC Solenoid is active and controlled above 25% duty cycle, with the Solenoid Supply voltage active.

• Set Condition:

  If the TCM detects on the TCC Solenoid control circuit a open, short to ground, short to voltage, internal short in the TCC Solenoid or open in the TCC Solenoid.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

Diagnostic Test

NOTE: If the TCM detects and stores a DTC, the TCM also stores the vehicles operating conditions under which the DTC originally set. This information is located in scan tool under Environmental Data. Before erasing any stored DTCs, record any available data to assist in duplicating the conditions in which the DTC originally set.

• Go To 2

• Go To 6

• Repair the (T75) TCC Solenoid Control circuit for an open.
• Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

• Go To 3

• Repair the (T75) TCC Solenoid Control circuit for a short to ground.
• Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

• Go To 4

• Repair the (T75) TCC Solenoid Control circuit for a short to another circuit.
• Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

• Go To 5

• Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM per the Service Information. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - REMOVAL)
• Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

• Replace the TCC Solenoid per the Service Information.
• Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

• Repair as necessary.
• Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

• Test Complete.