GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0045 00: Turbocharger Boost Pressure Output Circuit Open

DTC P0046 54: Turbocharger Boost Pressure Output Circuit High Temperature

DTC P0047 00: Turbocharger Boost Control Solenoid Control Circuit Low Voltage

DTC P0048 00: Turbocharger Boost Control Solenoid Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ignition

P0047 00

P0045 00

--

--

Control

P0047 00

P0045 00

P0048 00

P0046 54

Circuit/System Description

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane position control solenoid or a boost pressure actuator and a turbocharger pressure sensor to control the turbocharger vanes. The ECM will vary the boost dependant upon the load requirements of the engine. The ECM uses a pulse width modulation on the control circuit to control the solenoid valve.

Conditions for Running the DTC

    • The ignition is ON or the engine is running.
    • The ignition voltage is greater than 16.5 V.
    •  The ECM has commanded the turbocharger boost control solenoid ON and OFF at least once during the ignition cycle.
    • The DTCs run continuously once the above conditions are met.

Conditions for Setting the DTC

P0045 00, P0046 54, P0047 00 and P0048

The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.

P0045 54

The control module detects that the output driver chip temperature is too high.

Action Taken When the DTC Sets

DTCs P0045, P0047, and P0048 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0045, P0047, and P0048 are Type B DTCs.

Diagnostic Aids

Engine running, increase the engine speed to 1 500 RPM and maintain. With a scan tool, command the Turbocharger Vane Position Control Solenoid Valve OFF. The Turbocharger Vane Position Sensor parameter should increase to 95-97% when the Turbocharger Vane Position Control Solenoid Valve is commanded ON and decrease to near 0% when commanded OFF.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Description and Operation

Turbocharger System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, command the Turbocharger Vane Position between 0-5% with a scan tool. You should hear an audible click.
  2. Engine running, command the TC Vane Pos. Ctrl. Solenoid between 0-5% with a scan tool. You should hear an audible click.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the Q41 Turbocharger Vane Position Control Solenoid Valve.
  2. Test for less than 5 Ω between the ground circuit terminal 2 and ground.
  3. If greater than the specified range, repair the open/high resistance in the ground circuit.
  4. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground.
  5. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
  6. Test for 3-4 V between the control circuit terminal 4 and ground.
  7. If less than the specified range, test the control circuit for an open or a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).
    If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).
  8. Connect a test lamp between the control circuit terminal 4 and the ignition voltage circuit terminal 1.
  9. Clear the DTC information parameter with a scan tool. Command the Turbocharger Vane Position between 5-95% with a scan tool. The test lamp should illuminate brightly at 5%, and decrease up to 95%.
  10. If the test lamp does not respond to the scan tool commands replace the K20 Engine Control Module (ECM).
  11. If all circuits test normal, test or replace the Q41 Turbocharger Vane Position Control Solenoid Valve.

Component Testing

Static Test

  1. Ignition OFF, disconnect the harness connector at the Q41 Turbocharger Vane Position Control Solenoid Valve.
  2. Test for 3-5 Ω between the ignition terminal 1 and the control terminal 2 of the Q41 Turbocharger Vane Position Control Solenoid Valve.
  3. If not within the specified range, replace the Q41 Turbocharger Vane Position Control Solenoid Valve.
  4. Test for infinite resistance between each terminal and the Q41 Turbocharger Vane Position Control Solenoid Valve housing.
  5. If not the specified value, replace the Q41 Turbocharger Vane Position Control Solenoid Valve.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Turbocharger Wastegate Actuator Vacuum Control Solenoid Valve Splash Shield Removal
    •  Control Module References for engine control module replacement, setup, and programming