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

Short to Voltage

TC Vane Position Sensor 5-Volt Reference Circuit

P0652

P2564

--

TC Vane Position Sensor Signal Circuit

P2564

P2564

P2564

TC Vane Position Sensor Ground Circuit

--

P2564

--

Turbocharger Boost Control Solenoid Control Circuit

P0045

P0045

P0045

Circuit/System Description

The variable nozzle turbocharger (VNT) control solenoid valve is located in the turbocharger. The VNT control solenoid valve is controlled by the engine control module (ECM). The VNT control solenoid valve has a 12-volt reference circuit and a VNT control signal circuit. The ECM supplies voltage to the VNT control solenoid on the signal circuit. The VNT control solenoid valve is controlled by the time of voltage supply from the ECM to the VNT control solenoid valve. When the time of voltage supply increases, the VNT control solenoid valve position decreases.

Conditions for Running the DTC

    • The battery voltage is between 10-16 volts.
    • The ignition is ON for longer than 2 seconds.

Condition 1

    • VNT Duty Cycle is between 25-90 percent.
    • The ignition is OFF for longer than 2 seconds.

Condition 2

The VNT duty cycle is 0 percent for 5 seconds.

Conditions for Setting the DTC

Condition 1

The circuit current is less than 0.7 amps.

Condition 2

The VNT control signal is low when duty cycle is 0 percent.

Action Taken When the DTC Sets

    • DTC P0045 is a Type A DTC.
    • The malfunction indicator lamp (MIL) is illuminated.
    • The ECM records Freeze Frame data.

Conditions for Clearing the DTC

    • DTC P0045 is a Type A DTC.
    • The ECM turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

Inspect for any recent engine mechanical repairs. An incorrectly installed turbocharger boost control solenoid TC vane position sensor will cause this DTC to set.

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

    • Engine at idle, increase the TC vane position sensor in 5 percent increments, from 0-100 percent with a scan tool, while observing the TC Vane Position Sensor and the Desired TC Vane Position parameters. The parameters should remain within 2 percent of each other during the entire range.
    • Verify the integrity of the engine exhaust system by inspecting for the following conditions:
       - Damaged components
       - Loose or improper installation

Circuit/System Testing

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

  1. Ignition OFF, disconnect the harness connector at the VNT solenoid.
  2. Ignition ON, verify that a test lamp illuminates between the power supply circuit terminal 1 and ground.
  3. If the test lamp does not illuminate, test the power supply circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, disconnect the harness connector at the ECM.
  5. Install a 3-amp fused jumper wire between the power supply circuit terminal 1 and the control circuit.
  6. Ignition ON, verify that a test lamp illuminates between the control circuit at ECM terminal 2 and ground.
  7. If the test lamp does not illuminate, test the power supply circuit for a short to ground or an open/high resistance.
  8. Ignition OFF, test for between 3.4-4.1 ohms between the power supply circuit terminal 1 and control circuit terminal 2 at solenoid terminal.
  9. If resistance is more than 4 ohms or less than 3.1 ohms, test the solenoid for an open/high resistance. If the circuit tests normal, replace the ECM.
  10. Inspect the VNT solenoid.
  11. If abnormal condition detected, remove the VNT solenoid.

Component Testing

    • With the turbocharger solenoid disconnected, measure for a resistance of between 3.4-4.1 ohms across the turbocharger solenoid terminals.
       ⇒If the resistance is more than 4.1 ohms or less than 3.4 ohms, replace the solenoid or repair the circuit.
    • With the ignition OFF, remove the turbocharger vane position sensor. With the ignition ON, slowly depress the button on the end of the TC sensor.
    • Observe the TC vane position sensor parameter for a smooth decreasing percentage from 100-0 percent.
       ⇒If the parameter does not increment smoothly, replace the turbocharger vane position sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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