Circuit/System Testing

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: For vehicles equipped with a transfer case, review Diagnostic Aids.

Verify that OSS DTCs P0721, P0722, or P0723 are not set in the TCM.
- If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
Verify that ABS DTCs C0035-C0050, C1207-C1210, C1221-C1228, C1232-C1235, C005A, C0245, or C122E are not set in the electronic brake control module (EBCM).
- If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
Inspect the OSS, harness, and connector pins for metallic debris and the hybrid direct, 2-3-4 clutch housing assembly machined teeth for damage or misalignment. Even one bent or misaligned tooth, and or contact with the OSS, may cause this DTC to set. Proper torque of 9-13 N.m (80-115 lb in) to the OSS mounting bolt is critical to proper OSS operation. The hybrid system is very sensitive to the OSS signal for overall operation.
- If damage is observed, replace the damaged component.
Program the control module which set the DTC with the latest software version and retest for DTCs.
- If the DTC resets, replace the control module which set the DTC.