FixVault

Circuit/System Testing

WARNING: This page is about a different car, the 2009 GMC Canyon and 2009 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT: It is recommend that the defective components be replaced, and not the complete brake master cylinder assembly.
  1. Ignition OFF, disconnect the harness connector at the EBCM.
  2. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 23 and ground.
    • If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  3. If the circuits test normal, replace the EBCM.