CODE 39 TORQUE CONVERTOR CLUTCH (TCC) CIRCUIT

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steveX

CODE 39 TORQUE CONVERTOR CLUTCH (TCC) CIRCUIT

Post by steveX » Sun Apr 20, 2008 5:18 pm

CIRCUIT DESCRIPTION:The ECM controls Torque Converter Clutch (TCC) operation by grounding circuit (tan/black wire) throgh the quad-driver.
code 39 will set when:
* no code 29 is present.
* brake switch is closed "OFF" (brake is not applied).
* TCC is commanded "ON" by the ECM.
* Vehicle is in 4th gear
* the engine speed to vehicle speed ratio is outside of its window of operation.
* All of the above for a time greater than 30 seconds.

TEST DESCRIPTION:Number(s) refer to circled number(s) on the diagnostic chart.
1. Check fuse, brake switch and B+ circuit to the TCC solenoid.

2. Checks availability of B+ on purple brake input wire.

3. Electrical circuit have checked out, If these is a TCC engagement problem, see "hydraulics transmission faulty"

DIAGNOSTIC AIDS:A code 39 in combination with a code 38 would mean a problem with one or more of the following component. Fues,(pink and black wir), brake switch or wire before spice. A signal code 39 may be the result of a wire or purple wire problem between tcc solenoid and ECM, poor connection to ecm connection, or possibly the ECM.
If all circuit are OK, looking into internal trans faulty.



SOURCE: GM SERVICE MANUAL.

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