Circuit/System Verification
- Verify that DTC B137B or U189A are not present in the SDGM.
- If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose that DTC prior to this diagnostic.
- Verify the DTC U0074 is not set.
- If DTC U0074 is set as a current or history code, refer to DTC U0074 (HP2) or DTC U0074 (LML/LGH) .