• | 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. |
Voltage is provided to the exhaust gas recirculation (EGR) valve by the ignition 1 voltage circuit through a fuse. Ground is provided to the EGR valve on the control circuit by a low side driver within the engine control module (ECM). The ECM monitors the voltage on the control circuit of the EGR valve to determine if a failure is present.
• | The engine is running. |
• | The ignition voltage is less than 16.5 volts. |
• | The EGR is commanded ON. |
• | The DTCs run continuously when the above conditions are met. |
The ECM detects an open, short to ground or voltage on the control circuit of the EGR valve.
The ECM detects a short to voltage on the control circuit of the EGR valve.
The ECM detects a short to ground on the control circuit of the EGR valve.
The ECM detects an open circuit on the control circuit of the EGR valve.
The ECM detects that the internal output driver is over temperature.
The ECM detects an open or short to ground on the control circuit of the EGR valve.
The ECM detects a short to voltage on the control circuit of the EGR valve.
DTCs P0403, P0489, and P0490 are Type B DTCs.
DTCs P0403, P0489, and P0490 are Type B DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary. |
⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If not within the specified range, replace the ECM. |
⇒ | If not within the specified range, replace the EGR valve solenoid. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |