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 provide an overview of each diagnostic category. |
DTC Descriptor
DTC P0403: Exhaust Gas Recirculation (EGR) Solenoid Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
EGR Position Sensor 5-Volt Reference | P0652 | -- | P0409 | -- | -- |
EGR Position Sensor Low Reference | -- | -- | P0409 | -- | -- |
EGR Motor W Position Signal | P0409 | -- | P0409, P042E | -- | -- |
EGR Motor V Position Signal | P0409 | -- | P0409, P042E | -- | -- |
EGR Motor U Position Signal | P0409 | -- | P0409, P042E | -- | -- |
EGR Motor W Control | P0403 | -- | P0401, P0403 | -- | -- |
EGR Motor V Control | P0403 | -- | P0401, P0403 | -- | -- |
EGR Motor U Control | P0403 | -- | P0401, P0403 | -- | -- |
Circuit/System Description
The exhaust gas recirculation (EGR) valve is controlled by the engine control module (ECM) through the EGR motor high control and the EGR motor low control circuits. The ECM supplies voltage that is near ignition voltage to the high and low control circuits at all times. The ECM will pulse width modulation (PWM) the low control circuit to ground when EGR is desired. The lower the pulse width, the more the valve will open. The ECM will PWM the high control circuit to ground when the EGR valve is desired closed. If the ECM detects an electrical malfunction on the control circuits, DTC P0403 will set.
Conditions for Running the DTC
Condition 1
| • | DTCs P0404, P0409, P042E, P0652 and P0653 are not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The Ignition is ON for more than 2 seconds. |
OR
Condition 2
| • | DTCs P0652, P0653, P0409 and P0500 are not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The Ignition is ON for more than 2 seconds after the ignition switch is OFF. |
| • | The engine speed is 0 RPM. |
| • | The vehicle speed is 0 km/h (0 mph). |
Conditions for Setting the DTC
Condition 1
The EGR duty cycle is more than 70 percent for longer than 30 seconds.
OR
Condition 2
The ECM detects that the EGR valve position is not normal. The EGR position abnormal signal pattern is as follows:
| • | U, V, W position: ON, ON, ON |
| • | U, V, W position: OFF, OFF, OFF |
| • | U, V, W position: OFF, ON, ON |
| • | U, V, W position: OFF, ON, OFF |
| • | U, V, W position: OFF, OFF, ON |
Action Taken When the DTC Sets
DTC P0403 is a Type A DTC.
Conditions for Clearing the DTC
DTC P0403 is a Type A DTC.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
Important: If you cannot duplicate the condition, 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.
Command the EGR valve to 30 percent with a scan tool. The commanded EGR position and the Actual EGR position should match.
| ⇒ | If DTC P046C is also set, diagnose DTC P046C first. |
Circuit/System Testing
- Test the EGR valve control circuit for a short to ground, a short to voltage, or a short to each other. If the circuits are normal, replace the EGR valve.
- Connect all previously disconnected components.
- Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine and observe the scan tool current DTC information.
| ⇒ | If the DTC fails this ignition, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
