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Home >> Cadillac >> 2021 >> CT4 Sport, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 402 (Engine Controls And Fuel - 6.2L (LT4) - Diagnostic Information And Procedures (2 Of 3)) >> Diagnostic Information And Procedures >> DTC P0641, P0651, P0697, or P06A3 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2022 Cadillac CT5. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition/Vehicle - Off
  2. NOTE:

    Additional DTCs will set when disconnecting the components.

  3. Disconnect the electrical connector at one of the following components, depending on the DTC that is set:

    P0641

    • B23 Camshaft Position Sensor
    • B65 Manifold Absolute Pressure and Intake Air Temperature Sensor

    P0651

    • B1 A/C Refrigerant Pressure Sensor
    • B22 Brake Pedal Position Sensor - If equipped
    • B25B Clutch Pedal Position Sensor - If equipped
    • B26 Crankshaft Position Sensor
    • B37B Engine Oil Pressure Sensor
    • B105 Supercharger Air Inlet Pressure Sensor
    • B115 Vehicle Speed Sensor - If equipped
    • M128 Turbocharger Wastegate Actuator - If equipped
    • B227 Gear Position Sensor - If equipped
    • B310 Fuel Pressure and Temperature Sensor

    P0697

    • B107 Accelerator Pedal Position Sensor

    P06A3

    • B107 Accelerator Pedal Position Sensor
    • Q38 Throttle Body
  4. Ignition - On/Vehicle - In Service Mode
  5. Verify the scan tool parameter: Sensor Reference Circuit Status & Sensor Reference 2 - 4 Circuit Status = Malfunction - For the circuit that set the DTC.
    • If not the specified state after disconnecting a component from the circuit 

      Test or replace the component: The component that was disconnected last.

    • If the specified state and there are components connected to the circuit 

      Disconnect a component and repeat step 4.

    • Go to next step: If the specified state with all components disconnected from the circuit 
  6. Test for 4.8 to 5.2 V between the test points:
    • {P0641}5 V Reference circuit terminal 1 @B23 Camshaft Position Sensor & Ground
    • {P0651}5 V Reference circuit terminal 1 @B1 Air Conditioning Refrigerant Pressure Sensor & Ground
    • {P0697}5 V Reference circuit terminal 1 @B107 Accelerator Pedal Position Sensor & Ground
    • {P06A3}5 V Reference circuit terminal 5 @Q38 Throttle Body & Ground
    • If less than 4.8 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: K20 Engine Control Module
    3. Test for infinite resistance between the test points:

      P0641

      • 5 V Reference circuit terminal 57 X4@Control module harness & Ground
      • 5 V Reference circuit terminal 9 X4@Control module harness & Ground

      P0651

      • 5 V Reference circuit terminal 25 X4@Control module harness & Ground
      • 5 V Reference circuit terminal 39 X2@Control module harness & Ground

      P0697

      • 5 V Reference circuit terminal 45 X1 @Control module harness & Ground

      P06A3

      • 5 V Reference circuit terminal 38 X1@Control module harness & Ground
      • 5 V Reference circuit terminal 55 X4 @Control module harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: K20 Engine Control Module
    • If greater than 5.2 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: K20 Engine Control Module
    3. Ignition - On/Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:

      P0641

      • 5 V Reference circuit terminal 57 X4@Control module harness & Ground
      • 5 V Reference circuit terminal 9 X4@Control module harness & Ground

      P0651

      • 5 V Reference circuit terminal 25 X4@Control module harness & Ground
      • 5 V Reference circuit terminal 39 X2@Control module harness & Ground

      P0697

      • 5 V Reference circuit terminal 45 X1 @Control module harness & Ground

      P06A3

      • 5 V Reference circuit terminal 38 X1@Control module harness & Ground
      • 5 V Reference circuit terminal 55 X4 @Control module harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component: K20 Engine Control Module
    • Go to next step: If between 4.8 and 5.2 V 
  7. All OK.