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Home >> Hummer >> 2010 >> H3T Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 74 (Cruise Control System) >> Diagnostic Information and Procedures >> DTC P1574 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2010 GMC Canyon and 2010 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the cruise control release switch.
  2. Ignition ON, test for B+ between the B+ circuit terminal 1 and ground.
    • If less than the specified value, test the B+ circuit for a short to ground or an open/high resistance.
  3. Verify the scan tool TCC/Cruise Brake Pedal Switch parameter displays Released.
    • If not the specified value, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Install a 3A fused jumper wire between the signal circuit terminal 2 and the B+ circuit terminal 1. Verify the scan tool TCC/Cruise Brake Pedal Switch parameter displays Applied.
    • If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. If all circuits test normal, test or replace the cruise control release switch.