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: Turbocharger Boost Control Solenoid Control Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open or High Resistance

Short to Voltage

Signal Performance

Turbocharger Vane Position Solenoid High Control

P003A, P0045

P003A, P0045

P003A, P0045

P003A

Turbocharger Vane Position Solenoid Low Control

P003A, P0045

P003A, P0045

P0045, P003A

P003A

Circuit/System Description

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid valve and a turbocharger vane position sensor to control the turbocharger vanes. The ECM will vary the boost dependant upon the load requirements of the engine. The vane control solenoid valve has 2 circuits, a high control circuit and a low control circuit. The ECM uses a pulse width modulation on the control circuits to open and control the solenoid valve.

Conditions for Running the DTC

    • The engine run time is more than 60 seconds.
    • DTC P0045 runs continuously when the above condition is met.

Conditions for Setting the DTC

    • The control module detects that the commanded state of the driver and the actual state of the control circuit do NOT match.
    • The above condition exists for more than 1 second.

Action Taken When the DTC Sets

DTC P0045 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0045 is a Type B DTC.

Diagnostic Aids

    • If there is a loss of ignition voltage to terminal C1-76 at the ECM this DTC may set. Verify the circuit is not shorted to ground, open, or has an open supply fuse.
    • Engine running, increase the engine speed to 1,500 RPM and maintain. With a scan tool, command the TC Vane Pos. Ctrl. Solenoid ON and OFF. The TC Vane Position Sensor parameter should increase to 95-97 percent when the TC solenoid is commanded ON and decrease to near 0 percent when commanded OFF.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Controls Connector End Views
    •  Engine Controls Component Views
    •  Engine Control Module Connector End Views

Description and Operation

    •  Turbocharger System Description
    •  Turbocharger Learn

Electrical Information Reference

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Special Tools Required

J 34730-405 Injector Test Lamp

Circuit/System Verification

  1. If DTCs P0652, P0653, P0698, P0699, P2564, or P2565 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
  2. Engine running, increase the engine speed to 1,500 RPM and maintain. Command the TC Vane Pos. Ctrl. Solenoid ON and OFF with a scan tool. Observe the Vane Position Sensor parameter. The TC Vane Position Sensor parameter should increase to 95-97 percent and decrease to near 0 percent when commanded ON and OFF.
  3. Engine running, observe the TC Vane Position Sensor and the Desired TC Vane Position parameters with a scan tool. Slowly increase the engine speed from idle to 2,500 RPM, and slowly return the engine to idle speed. The TC Vane Position Sensor parameter should remain near or equal to the Desired TC Vane Position parameter throughout the engine speed range.
  4. Engine running, observe the TC Vane Position Sensor and the Desired TC Vane Position parameters while increasing the TC vane pone position in 5 percent increments from 0-100 percent with a scan tool. The parameters should remain within 2 percent of each other during the entire range.
  5. Engine running, observe the DTC information with a scan tool. DTC P0045 should not set.
  6. 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.

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

  1. Ignition OFF, allow sufficient time for the ECM to power down.
  2. Disconnect the harness connector at the TC vane position solenoid.
  3. Connect the J 34730-405 between the high control and the low control circuits.
  4. Ignition ON, command the TC Van Pos. Ctrl. solenoid ON and OFF with a scan tool. The test lamp should change from Bright to Dim when changing between the commanded states.
  5. If the test lamp does NOT change brightness, test the low control circuit for a short to voltage. If the circuit tests normal, test the low control and high control circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM.
  6. Engine running, observe the TC Vane Pos. Ctrl. Solenoid Amperage parameter for a value of 0.4-1.1 amps.
  7. If the value is less than 0.4 amp, test the high control circuit for a short to voltage.
  8. Ignition OFF, disconnect the harness connectors at the ECM, TC vane position sensor, and the TC vane position solenoid.
  9. Test for less than 5 ohms of resistance on all circuits between the following terminals:
  10. • The ECM C1 solenoid high control circuit terminal 48 to TC solenoid terminal A
    • The ECM C1 solenoid low control circuit terminal 96 to TC solenoid terminal B
    • The ECM C1 sensor signal circuit terminal 20 to TC sensor terminal C
    • The ECM C1 sensor low reference terminal 63 to TC sensor terminal B
    • The ECM C1 sensor 5-volt reference terminal 13 to TC sensor terminal A
    If the resistance is over 5 ohms, repair the high resistance in the affected circuit.
  11. Remove the TC solenoid from the turbocharger. Connect the ECM and the turbocharger solenoid connectors.
  12. Ignition ON, depress the button at the tip of the solenoid slightly. Command the TC Vane Pos. Ctrl. Solenoid ON while observing for the spool valve to open at the slot closest to the button.
  13. If the spool valve did not operate, replace the TC solenoid.
  14. Inspect the turbocharger for debris, damage, or sticking vanes. Refer to Turbocharger Cleaning and Inspection .
  15. If all circuits, the TC vane position solenoid, and the TC vane position sensor tests normal, replace the turbocharger assembly.

Component Testing

Important: You must perform the Circuit/System Testing before proceeding with the Component Testing.

  1. Ignition OFF, disconnect the wire harness at the TC solenoid. Test for a resistance of less than 7 ohms across the TC solenoid.
  2. If the resistance is more than more than 7 ohms, replace the TC solenoid.
  3. Test the infinite resistance between each terminal and the TC solenoid housing.
  4. If less than infinite resistance, replace the TC solenoid.
  5. Ignition OFF, remove the TC vane position sensor.
  6. Connect the harness connector to the TC vane position sensor.
  7. Ignition ON, slowly depress the button on the end of the TC vane sensor. Observe the TC Vane Position Sensor parameter for a smooth decreasing percentage from 100-0 percent without any spikes or dropouts.
  8. If the TC Vane Position Sensor parameter does not increment smoothly, replace the TC vane position sensor.

Repair Instructions

Perform the Turbocharger Learn Procedure. Refer to Turbocharger Learn , then review the DTC information with a scan tool.

    •  Turbocharger Vane Position Sensor Replacement
    •  Turbocharger Control Solenoid Valve Replacement
    •  Turbocharger Replacement
    •  Control Module References for ECM replacement, setup, and programming

Repair Verification

  1. Engine running, observe the scan tool TC Vane Position Sensor and the Desired TC Vane Position parameters. Slowly increase the engine speed to 2,500 RPM, and slowly return the engine speed to idle. The TC Vane Position parameter should remain near or equal to the Desired TC Vane Position parameter.
  2. Engine running, observe the scan tool TC Vane Position Sensor parameter while increasing the engine speed to 1,500 RPM and maintaining. Command the TC Vane Pos. Ctrl. Solenoid ON and OFF. The TC Vane Position Sensor parameter should increase to 95-97 percent when the TC solenoid is commanded ON, and decrease to near 0 percent when commanded OFF.
  3. Engine running, observe the scan tool TC Vane Position Sensor and the Desired TC Vane Position parameters while increasing the TC vane position sensor in 5 percent increments from 0-100 percent. The TC Vane Position Sensor and the desired TC Vane Position parameters should remain within 2 percent of each other during the entire range.