LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1580 (Antilock Brake System - Hybrid (Hp2) With Traction Control System & Stability Control System) >> Diagnostic Information and Procedures >> DTC C0277, C120C, C129A, C129B, C129D, C129E, C12B1, or C12F8 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform a hydraulic check, refer to Brake Hydraulic and Assist System Diagnosis (Two-mode Hybrid) .
  2. Ignition OFF, disconnect the harness connector at the brake master cylinder piston position sensor.
  3. Wait 60 seconds, test for less than 5 Ω between the low reference circuit terminal 4 and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
  4. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground.
    • If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
    • If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
  5. Verify the scan tool BMC Primary Piston Position Sensor A parameter is less than 1 V.
    • If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the EBCM.
  6. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 2. Verify the scan tool BMC Primary Piston Position Sensor A parameter is greater than 4.5 V.
    • 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 EBCM.
  7. Verify the scan tool BMC Primary Piston Position Sensor B parameter is less than 1 V.
    • If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the EBCM.
  8. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5 V reference circuit terminal 2. Verify the scan tool BMC Primary Piston Position Sensor B parameter is greater than 4.5 V.
    • 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 EBCM.
  9. If all circuits test normal, replace the brake master cylinder piston position sensor.
scientia non olet · About LEMON Manuals