LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1643 (Engine Control System & Fuel System - 4.8L, 5.3L, 6.0L, 6.2L - DTC P0010 To DTC P0232/DTC P025A) >> DTC P0120, P0122, P0123, P0220, P0222, P0223, or P2135 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the throttle body assembly.
  2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 Ω between the low reference circuit terminal C 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 ECM.
  3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal E 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 ECM.
    • If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Test for less than 1 V between the TP sensor 1 signal circuit terminal D and ground.
    • If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  5. Install a 3 A fused jumper wire between TP sensor 1 signal circuit terminal D and the 5 V reference circuit terminal E. Verify the scan tool TP sensor 1 voltage parameter is greater than 4.8 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 ECM.
  6. Test for 4.8-5.2 V between the TP sensor 2 signal circuit terminal F and ground.
    • If less than 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 specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  7. If all circuits test normal, test or replace the throttle body assembly.
scientia non olet · About LEMON Manuals