2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1187

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1187

DTC P0244-P0246

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC P0244

- Turbocharger Wastegate Solenoid Valve Control Performance

DTC P0245

- Turbocharger Wastegate Solenoid Valve Control Circuit Low Voltage

DTC P0246

- Turbocharger Wastegate Solenoid Valve Control Circuit High Voltage

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) controls boost using the turbocharger wastegate solenoid valve. The wastegate valve is actuated by a rod from

the diaphragm box located at the housing. A spiral spring in the diaphragm box works in the closing direction while the pressure in the diaphragm

works in the opening direction. The ECM supplies a pulse width modulation (PWM) signal to a solenoid valve, which then allows pressure from

the turbo to come through. When the pressure overcomes the spring force in the diaphragm box, the rod begins to move, opening the wastegate

valve to a corresponding degree. The ECM changes wastegate valve opening by varying the PWM signal, which regulates the turbine speed.

Ignition voltage is supplied directly to the wastegate solenoid valve. The ECM controls the solenoid valve by grounding the control circuit with a

solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control

circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

Conditions for Running the DTCs

* The engine speed is greater than 80 RPM.

* The battery voltage is between 10-18 V.

* The ECM has commanded the wastegate solenoid valve ON and OFF at least once during the ignition cycle.

* The DTCs run continuously within the enabling conditions.

Conditions for Setting the DTCs

P0244

The ECM detects the wastegate solenoid valve control circuit is open.

P0245

The ECM detects the wastegate solenoid valve control circuit is shorted to ground.

P0246

The ECM detects the wastegate solenoid valve control circuit is shorted to voltage.

Action Taken When the DTCs Set