Circuit/System Testing
WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect the X2 B15 transmission internal mode switch harness connector at the Q8 control solenoid valve assembly. Ignition ON. The scan tool IMS A/B/C/P parameter should display HI for all 4 signal circuits.
- If a signal circuit displays LOW, replace the Q8 control solenoid valve assembly.
- Connect a 3-amp fused jumper wire between each transmission range signal circuit at the Q8 control solenoid valve assembly and ground. With a scan tool, ensure that each signal circuit displays LOW when connected to ground.
- If a signal circuit remains HI when connected to ground, replace the Q8 control solenoid valve assembly.
- Connect the B15 transmission internal mode switch harness connector to the Q8 control solenoid valve assembly. Disconnect the B15 transmission internal mode switch connector. The scan tool B15 transmission internal mode switch A/B/C/P parameter should display HI for all 4 signal circuits.
- If a signal circuit displays LOW, replace the B15 transmission internal mode switch jumper harness.
- Connect a 3-amp fused jumper wire between each transmission range signal circuit at the B15 transmission internal mode switch connector harness and ground. With a scan tool, ensure that each signal circuit displays LOW when connected to ground.
- If a signal circuit remains HI when connected to ground, replace the B15 transmission internal mode switch harness.
- If a signal circuit other than the circuit being grounded displays LOW, replace the B15 transmission internal mode switch harness.
- If all circuits test normal, replace the B15 transmission internal mode switch.
NOTE:
Damage to the TCM may occur if the X1 16 way harness connector is disconnected before the X176 24 way connector or if the X1 16 way harness connector is connected after the X176 24 way connector.