GM Service Manual Online
For 1990-2009 cars only

Circuit Description


Object Number: 902637  Size: MF

Second clutch is applied when circuit 1222 is opened at the PCM. When the PCM opens the circuit, the voltage is monitored at terminal J4A07 to check for proper circuit conditions.

Conditions for Setting the DTC

DTC P0756 is set when the PCM has detected voltage monitored at terminal J4A07, circuit 1222, is less than 2-2.5 volts when the 2nd gear solenoid is switched OFF electrically by the PCM, twice per ignition cycle.

Test Description

Numbered steps below refer to numbered steps on the chart.

  1. This step verifies the problem is still present.
  2. If the TRS 2/TCC fuse is OK, check for battery voltage on the fuel pump relay side of the fuse with the engine running.
  3. This step checks for a ground in circuit 1526. A ground in circuit 1526 will cause the TRS 2 fuse to fail and set DTC P0756.
  4. An open in circuit 1526 will cause DTC P0756 to set. Check circuit 1526 for opens.
  5. This step determines if the fault is in the circuit to the PCM or in the solenoid or connector plate.
  6. This step will determine if fault is in the solenoid or connector plate.
  7. An open or a ground in circuit 1222 will set DTC P0756. This step checks circuit 1222 for opens or grounds.

Repair Verification

Monitor the DTC menu Code Status for Pass Since Code Clear and Pass This Ignition Cycle. When both have passed, the repair is verified.

Criteria for pass:

    • The engine is running.
    • Power is present at the solenoids and no active faults exist for this solenoid.

Diagnostic Aids

This DTC may set or intermittent 2nd gear starts may be caused by a poor electrical connection at either the PCM, solenoid connector plate, or UHJB terminals. Wiggle the connectors while performing an actuator quick test may help isolate the problem area.

When the PCM detects a fault in the circuit, and open, ground, or short, the PCM will open the circuit internally to protect the circuit.

An open will result in 2nd gear being stuck on and a DTC P0741. A grounded circuit 1222 will result in no 2nd gear, no reverse, and a DTC P0732.


Object Number: 903278  Size: FP

Object Number: 902660  Size: FP