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Home >> Chevrolet >> 2023 >> Tahoe SSV >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 7 (Engine Controls And Fuel - 3.0L (Lm2) Diesel - Diagnostic Information And Procedures (3 Of 5)) >> Diagnostic Information and Procedures >> DTC P0641, P0651, P0697, or P06A3 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  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

    • B23E Camshaft Position Sensor - Exhaust
    • B65 Intake Manifold Pressure and Air Temperature Sensor
    • Q14A Exhaust Gas Recirculation Valve 1
    • Q14B Exhaust Gas Recirculation Valve 2
    • M103 Turbocharger Vane Position Actuator
    • M122 Exhaust Pressure Regulator Valve

    P0651

    • B1 A/C Refrigerant Pressure Sensor
    • B22 Brake Pedal Position Sensor
    • B26 Crankshaft Position Sensor
    • B321 Crankcase Pressure Sensor
    • B345P Exhaust Pressure Differential Sensor - Particulate Filter
    • B345R Exhaust Pressure Differential Sensor - Exhaust Gas Recirculation
    • B37B Engine Oil Pressure Sensor
    • Q22 Intake Manifold Tuning Solenoid Valve
    • Q38 Throttle Body
    • Q74 Engine Coolant Bypass Valve
    • Q97M Engine Coolant Flow Control Valve - Main

    P0697

    • B107 Accelerator Pedal Position Sensor2

    P06A3

    • B47B Fuel Rail Pressure Sensor
    • B107 Accelerator Pedal Position Sensor1
  4. Ignition - On/Vehicle - In Service Mode
  5. Verify the scan tool parameter: Sensor Reference 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 - Sensor Reference Circuit

    • 5 V Reference circuit terminal 1@B23 Camshaft Position Sensor & Ground
    • 5 V Reference circuit terminal 2@B65 Intake Manifold Pressure and Air Temperature Sensor & Ground
    • 5 V Reference circuit terminal 1@Q14A Exhaust Gas Recirculation Valve 1 & Ground
    • 5 V Reference circuit terminal 3@Q14B Exhaust Gas Recirculation Valve 2 & Ground
    • 5 V Reference circuit terminal 4@M103 Turbocharger Vane Position Actuator & Ground
    • 5 V Reference circuit terminal 3@M122 Exhaust Pressure Regulator Valve & Ground

    P0651 - Sensor Reference 2 Circuit

    • 5 V Reference circuit terminal 1@B1 A/C Refrigerant Pressure Sensor & Ground
    • 5 V Reference circuit terminal 6@B22 Brake Pedal Position Sensor & Ground
    • 5 V Reference circuit terminal 1@B26 Crankshaft Position Sensor & Ground
    • 5 V Reference circuit terminal 3@B37B Engine Oil Pressure Sensor & Ground
    • 5 V Reference circuit terminal 1@B321 Crankcase Pressure Sensor & Ground
    • 5 V Reference circuit terminal 1@B345P Exhaust Pressure Differential Sensor - Particulate Filter & Ground
    • 5 V Reference circuit terminal 1@B345R Exhaust Pressure Differential Sensor - Exhaust Gas Recirculation & Ground
    • 5 V Reference circuit terminal 3@Q22 Intake Manifold Tuning Solenoid Valve & Ground
    • 5 V Reference circuit terminal 5@Q38 Throttle Body & Ground
    • 5 V Reference circuit terminal 3@Q74 Engine Coolant Bypass Valve & Ground
    • 5 V Reference circuit terminal 3@Q97M Engine Coolant Flow Control Valve - Main & Ground

    P0697 - Sensor Reference 3 Circuit

    • 5 V Reference circuit terminal 6@B107 Accelerator Pedal Position Sensor - Sensor 2 & Ground

    P06A3 - Sensor Reference 4 Circuit

    • 5 V Reference circuit terminal 1@B47B Fuel Rail Pressure Sensor & Ground
    • 5 V Reference circuit terminal 1@B107 Accelerator Pedal Position Sensor - Sensor 1 & Ground
    • If less than 4.8 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the appropriate electrical connector: K20 Engine Control Module
    3. Test for infinite resistance between the test points:

      P0641

      • 5 V Reference circuit terminal 5 X2 @Control module harness & Ground
      • 5 V Reference circuit terminal 70 X1 @Control module harness & Ground

      P0651

      • 5 V Reference circuit terminal 7 X2 @Control module harness & Ground
      • 5 V Reference circuit terminal 48 X1 @Control module harness & Ground

      P0697

      • 5 V Reference circuit terminal 71 X1 @Control module harness & Ground

      P06A3

      • 5 V Reference circuit terminal 66 X2 @Control module harness & Ground
      • 5 V Reference circuit terminal 72 X1 @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 appropriate 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 5 X2 @Control module harness & Ground
      • 5 V Reference circuit terminal 70 X1 @Control module harness & Ground

      P0651

      • 5 V Reference circuit terminal 7 X2 @Control module harness & Ground
      • 5 V Reference circuit terminal 48 X1 @Control module harness & Ground

      P0697

      • 5 V Reference circuit terminal 71 X1 @Control module harness & Ground

      P06A3

      • 5 V Reference circuit terminal 66 X2 @Control module harness & Ground
      • 5 V Reference circuit terminal 72 X1 @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.