Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Verify the following DTCs are not set in the modules as follows:
- SDGM - U1818
- HPCM - U189A
- If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose that DTC prior to this diagnostic.
- Ignition OFF, disconnect the harness connector of the yaw rate and lateral acceleration sensor.
- Verify that a test lamp illuminates between the ground circuit terminal 6 and B+.
- If the test lamp does not illuminate, test the circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the EBCM.
- Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground.
- If the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
- Ignition OFF, disconnect harness connector X1 of the SDGM.
- Test for less than 1.0 ohm between the SDGM and the yaw rate and lateral acceleration sensor on the following circuit terminals.
- PTLAN + SDGM terminal 14 and yaw rate and lateral acceleration sensor terminal 2
- PTLAN - SDGM terminal 12 and yaw rate and lateral acceleration sensor terminal 3
- If greater than the specified range, test the circuit for an open/high resistance.
- If the circuits test normal, replace the SDGM.