Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
It is recommend that Component Testing is performed before Circuit Testing when diagnosing the power brake booster actuator.
- Ignition OFF, disconnect the 2 way harness connector at the power brake booster actuator.
- Test for less than 25.0 ohm of resistance between the ground circuit terminal 5 and ground.
- If greater than 25.0 ohm, test the ground circuit for an open/high resistance.
- Connect a test lamp between the control circuit terminal 1 and the ground circuit terminal 5.
- Command the Active Brake Booster to ON and OFF with a scan tool.
- If the test lamp remains OFF during the commands, test for a short to ground or an open/high resistance on either control circuit. If the circuits test normal, replace the EBCM.
- If the test lamp is always ON, test the control circuits for a short to battery positive. If the circuit tests normal, replace the electronic brake control module (EBCM).
- If all circuits test normal, test or replace the vacuum brake booster assembly.