LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2021 >> CT4 Sport, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 129 (Engine Controls And Fuel - 3.6L (LF4) - Diagnostic Information And Procedures (1 Of 3)) >> Diagnostic Information and Procedures >> DTC P0090-P0092, P00C9, P00CA, or P163A >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition - On / Vehicle - In Service Mode
  2. Perform the scan tool control function: Fuel Pressure Regulator - On and Off

    Verify the scan tool parameter:

    • Fuel Pressure Regulator Control Circuit High Test Status = Not Run or Okay
    • Fuel Pressure Regulator Control Circuit Low Test Status = Not Run or Okay
    • Fuel Pressure Regulator Control Circuit Open Test Status = Not Run or Okay
    • Fuel Pressure Regulator High Control Circuit High Test Status = Not Run or Okay
    • Fuel Pressure Regulator High Control Circuit Low Test Status = Not Run or Okay
    • Fuel Pressure Regulator High Control Circuit Open Test Status = Not Run or Okay
    • If not the specified state 

      Refer to: Circuit/System Testing

    • Go to next step: If the specified state 
  3. Perform the scan tool control function: Fuel Pressure Regulator - On and Off

    Verify a click can be heard or felt at the following component (s) when the scan tool control function was commanded: G18 Fuel Pump - High Pressure

    • If a click cannot be heard or felt 

      Refer to: Circuit/System Testing

    • Go to next step: If a click can be heard or felt 
  4. Perform the scan tool control function: Fuel Pressure Regulator - On - Command the function On several times.

    Verify the scan tool parameter:

    • Fuel Pressure Regulator Control Circuit High Test Status = Not Run or Okay
    • Fuel Pressure Regulator Control Circuit Low Test Status = Not Run or Okay
    • Fuel Pressure Regulator Control Circuit Open Test Status = Not Run or Okay
    • Fuel Pressure Regulator High Control Circuit High Test Status = Not Run or Okay
    • Fuel Pressure Regulator High Control Circuit Low Test Status = Not Run or Okay
    • Fuel Pressure Regulator High Control Circuit Open Test Status = Not Run or Okay
    • Perform the action while monitoring the parameter:
    • Wiggle the harness and connector: G18 Fuel Pump - High Pressure
    • Wiggle the harness and connector: K20 Engine Control Module
    • If not the specified state 

      Repair as necessary - Wiring / Terminal (s) / Electrical Connector (s)

    • Go to next step: If the specified state 
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

    Verify the DTC does not set.

    • If the DTC sets 

      Refer to: Circuit/System Testing

    • Go to next step: If the DTC does not set 
  6. All OK.
scientia non olet · About LEMON Manuals