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 Descriptors

DTC P2564: Turbocharger Boost Control Position Sensor Circuit Low Voltage

DTC P2565: Turbocharger Boost Control Position Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Turbocharger Vane Position Sensor 5-Volt Reference

P0698, P2564

P003A, P2563

P2564

P0699, P2565

P2563

Turbocharger Vane Position Sensor Signal Circuit

P2564

P2563

P2564

P2565

P2563

Turbocharger Vane Position Sensor Low Reference Circuit

--

P003A, P2563

P2565

--

P2563

Typical Scan Tool Data

TC Vane Position Sensor

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Engine Running

Parameter Normal Range: Varies, TC Vane Position Sensor Parameter Matches Desired TC Vane Position Parameter

5-Volt Reference Circuit

0%

--

100%

Turbocharger Vane Position Sensor Signal Circuit

0%

0%

100%

Low Reference Circuit

--

100%

--

Circuit/System Description

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM commands the TC vane position solenoid to change the position of vanes in order to vary boost depending upon the load requirements of the engine. The TC vane position sensor provides the ECM with a signal voltage relative to position of the turbocharger vanes.

Conditions for Running the DTC

P2564

    • The engine has been running for more than 3 seconds.
    • DTC P2564 and P2565 run continuously when the above conditions are met.

P2565

    • The engine has been running for more than 3 seconds.
    • DTC P2564 and P2565 run continuously when the above conditions are met.

Conditions for Setting the DTC

P2564

The ECM detects that the turbocharger vane position sensor voltage is less than 0.28 volt for greater than 1 second.

P2565

The ECM detects that the turbocharger vane position sensor signal voltage is greater than 4.7 volts for greater than 1 second.

Action Taken When the DTC Sets

DTCs P2564 and P2565 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P2564 and P2565 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation Reference

    •  Turbocharger Learn
    •  Turbocharger System Description

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

  1. Verify that DTCs P0698 or P0699 are not set.
  2. If any of the DTCs are set, refer to DTC P0698 or P0699 .
  3. Engine running, observe the scan tool TC Vane Position Sensor and the Desired Vane Position parameters while slowly increasing the engine speed to 2,500 RPM, then returning the engine speed to idle. The TC Vane Position Sensor parameter should remain near or equal to the Desired Vane Position parameter.
  4. 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

  1. Ignition OFF, disconnect the harness connector at the TC vane position sensor.
  2. Ignition OFF and scan tool disconnected for 90 seconds, test for less than 5 ohms between the low reference terminal C and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal D and ground.
  5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Verify the scan tool TC Vane Position Sensor parameter is less than 2 percent.
  7. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM.
  8. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal D. Verify the scan tool TC Vane Position Sensor parameter is greater than 98 percent.
  9. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  10. If all circuits test normal, test the TC vane position sensor.

Component Testing

Important: You must perform the Circuit/System Testing in order to verify the integrity of the TC vane position sensor circuits before proceeding with Component Testing.

Erratic Signal Test

  1. Ignition OFF, disconnect the harness connector at the TC vane position sensor.
  2. Remove the TC vane position sensor.
  3. Connect the TC vane position sensor harness connector.
  4. Ignition ON, observe the scan tool TC Vane Position Sensor parameter while slowly depressing the button at the end of the sensor. There should be a smooth percentage change without any spikes or drop-outs.
If the TC Vane Position parameter does not increment smoothly or is erratic, replace the TC vane position sensor.

Repair Instructions

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

Repair Verification

  1. Install any components or connectors that have been removed or replaced during diagnosis.
  2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
  3. Clear the DTCs.
  4. Turn OFF the ignition for 60 seconds.
  5. Duplicate the Conditions for Running the DTC and use the freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
  6. If any service has been performed on the turbocharger or on the turbocharger components, a turbocharger relearn must be performed. Failure to perform the turbocharger learn procedure may cause this DTC to set. Refer to Turbocharger Learn .