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Home >> GMC >> 2018 >> Terrain SL >> Repair and Diagnosis (Single Page) >> Electrical >> Charging Systems >> 12 V Starting And Charging System >> Diagnostic Information And Procedures >> DTC P15A3: Stop/Start Select Switch Circuit Signal Message Counter Incorrect >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the S124 Stop/Start Select Switch.
  2. Test for less than 10 Ω between the ground circuit terminal 1 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω at the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • Go to next step: If less than 10 Ω 
  3. Ignition ON, verify with a scan tool the Engine control Module Stop/Start Select Switch parameter is No.
    • If the parameter is YES 
    1. Ignition OFF, disconnect the harness connector X3 at the K9 Body Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground at the circuit.
      • If infinite resistance, replace the K9 Body Control Module.
    • Go to next step: If the parameter is NO 
  4. Install a 3 A fused jumper wire between the signal circuit terminal 3 and ground. Verify the ECM scan tool Stop/Start Select Switch parameter is Yes.
    • If the parameter is NO 
    1. Ignition OFF.
    2. Disconnect the harness connector X3 at the K9 Body Control Module.
    3. Test for less than 1 V the control circuit and ground.
      • If greater than 1 V, repair the short to voltage.
      • If less than 1 V, replace the K9 Body Control Module.
    • Go to next step: If the parameter is YES 
  5. Test or replace the S124 Stop/Start Select Switch.
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