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Home >> Cadillac >> 2009 >> CTS V, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 6.2L - DTC P0016 To DTC P0175 >> DTC P012C or P012D >> Circuit/System Testing

Circuit/System Testing

NOTE: You must perform the Circuit/System Verification before proceeding with the Circuit/System Testing.
  1. Verify the integrity of the SCIAP sensor system by inspecting for the following conditions:
    • Any damage to the SCIAP sensor housing
    • A loose or improperly installed SCIAP sensor
    • A restriction in the vacuum source of the SCIAP sensor
  2. Ignition OFF, disconnect the harness connector at the SCIAP sensor.
  3. Ignition OFF for 90 seconds, test for less than 5Ω between the low reference circuit terminal 2 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.
  4. Ignition ON, test for 4.8-5.2V between the 5V reference circuit terminal 1 and ground.
    • If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. Verify the scan tool SC Inlet Pressure Sensor parameter is less than 20 kPa.
    • If the greater than the specified parameter, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Install a 3A fused jumper wire between the 5V reference circuit terminal 1 and the signal circuit terminal 3. Verify the scan tool parameter is greater than 95 kPa.
    • If less than the specified parameter, test the signal circuit for a short to ground, open/high resistance. If the circuit tests normal, replace the ECM.
  7. If all circuits test normal, test or replace the SCIAP sensor.
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