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 P0244: Turbocharger Wastegate Solenoid Control Circuit

DTC P0245: Turbocharger Wastegate Solenoid Control Circuit Low Voltage

DTC P0246: Turbocharger Wastegate Solenoid Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Ignition 1 Voltage Circuit

P0010, P0013, P0033, P0034, P0245, P2088, P2090

P0244

P0244, P0245

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Turbocharger Wastegate Solenoid Control Circuit

P0245

P0244

P0244

P0246

P0244

Circuit/System Description

The BorgWarner™ dual-scroll turbocharger (TC) incorporates a wastegate that is controlled by a pressure differential, that is determined by the engine control module (ECM) by means of a PWM solenoid, in order to regulate the pressure ratio of the compressor. A charge air bypass valve also controlled by the ECM by utilizing a remotely mounted solenoid is integrated into the unit to prevent compressor surging and damage from vibrations by opening during abrupt closed throttle conditions. When the bypass valve is open during closed throttle deceleration conditions, the bypass valve allows the air to recirculate in the turbocharger and maintain compressor speed. Within a calibrated range during the closed throttle event, or upon a wide open throttle command the bypass valve will then close to optimize turbo response. The TC wastegate actuator has the following circuits:

    • Ignition 1 voltage
    • Turbocharger wastegate solenoid control

At idle the TC Wastegate Solenoid parameter is commanded to 0 percent by the ECM. When the engine load and RPM first increases under a wide open throttle, the TC Wastegate Solenoid parameter should briefly be commanded as great as 90-100 percent. When the proper level of boost pressure is attained, the ECM will decrease the PWM of the solenoid to a range of 65-85 percent. As soon as the throttle closes the ECM will command the TC Wastegate Solenoid parameter back to 0 percent, in order to allow the turbocharger waste gate to open from the air pressure ratio differential, thereby reducing the speed of the turbine.

Conditions for Running the DTCs

    • The engine speed is greater than 80 RPM.
    • The battery voltage is between 10-18V.
    • This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTCs

The ECM detects an open, a short to ground, or a short to voltage on the TC wastegate solenoid control circuit for greater than 4 seconds continuously, or 50 seconds cumulative.

Action Taken When the DTCs Set

    • DTCs P0244, P0245, and P0246 are Type C DTCs.
    • An indicator will illuminate.
    • The ECM will disable boost control and limit the system to mechanical boost only, resulting in a substantial decrease in engine power.

Conditions For Clearing the MIL/DTC

DTCs P0244, P0245, and P0246 are Type C DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

    •  Turbocharger System Description
    •  Boost Control 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

    • Perform an inspection of the TC.
    • Use the scan tool output controls to command the TC Wastegate Solenoid parameter from 0-100 percent. An audible series of clicks when the command is between 20-90 percent should be heard and felt.
    • 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. Clear the DTCs with a scan tool.
  2. Inspect for damage to the TC wastegate actuator.
  3. Ignition OFF, disconnect the harness connector at the Q42 TC wastegate actuator.
  4. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal 2 and ground.
  5. If a test lamp does not illuminate test the voltage supply circuit for a short to ground or an open/high resistance.
  6. Verify that a test lamp does not illuminate between the control circuit terminal 1 and ground.
  7. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
  8. Connect a test lamp between the control circuit terminal 1 and the voltage supply circuit terminal 2.
  9. Command the TC Wastegate Solenoid parameter to 50 percent with a scan tool. The test lamp should illuminate and flash rapidly when commanded to 50 percent and turn OFF when commanded to 0 percent.
  10. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
    If the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  11. If the circuits test normal, test or replace the Q42 TC wastegate actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming