LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1704 (Engine Controls And Fuel - 3.6L (LCS) - DTC P0638 To DTC P2229) >> DTC P2122, P2123, P2127, P2128, or P2138 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, open the hood to disable the Auto-Stop function.
  2. Ignition ON, verify the scan tool hood position parameter displays Open.
    • If the hood position does not display Open, refer to DTC P254F .
  3. Ignition OFF, remove the fuse that supplies B+ to circuit terminal X2-56 of the ECM.
  4. Disconnect the harness connector at the accelerator pedal assembly.
  5. Test for less than 5 Ω between the low reference circuit terminals listed below and ground.
    • Low reference circuit terminal A
    • Low reference circuit terminal D
    • If greater than the specified range, test the appropriate low reference circuit for a short to voltage, or an open/high resistance. If the circuit tests normal, replace the ECM.
  6. Install the fuse that supplies B+ to circuit terminal X2-56 of the ECM.
    7. NOTE: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.
  7. Ignition ON, test for 4.8-5.2 V between both 5-volt reference circuit terminals listed below and ground.
    • 5 volt reference circuit terminal C
    • 5 volt reference circuit terminal F
    • If less than the specified range, test the appropriate 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the appropriate 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  8. Verify the appropriate APP sensor voltage parameter is at 0 V.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  9. Install a 3 A fused jumper wire between the appropriate signal circuit listed below and the 5-volt reference circuit terminal F. Verify the APP sensor voltage parameter is greater than 4.8 V.
    • APP sensor 1 signal circuit terminal E
    • APP sensor 2 signal circuit terminal B
    • If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  10. If all circuits test normal, replace the accelerator pedal assembly.
scientia non olet · About LEMON Manuals