DTC P0403, P0489, or P0490

 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 P0403 04

Exhaust Gas Recirculation (EGR) Control Circuit Open

 DTC P0489 02

Exhaust Gas Recirculation (EGR) Motor Control Circuit Short to Ground

 DTC P0489 12

Exhaust Gas Recirculation (EGR) Motor Control Circuit Low Input

 DTC P0490 01

Exhaust Gas Recirculation (EGR) Motor Control Circuit Short to Battery

 DTC P0490 11

Exhaust Gas Recirculation (EGR) Motor Control Circuit High Input

 Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Control

 P0404 03, P0489 02, P0489 12

 P0403 04

 P0490 01, P0490 11

 P0404 0B, P0404 51, P0404 52, P0404 52, P0404 5B, P0404 5A, P0404 56, P0404 55, P0404 59
Ground

 -

 -

 -

 -


 Circuit/System Description

The exhaust gas recirculation (EGR) valve is controlled by the engine control module (ECM) through the EGR solenoid. A reference voltage is transferred to the EGR valve's solenoid valve. The ECM controls the solenoid valve by grounding the control circuit.

 Conditions for Running the DTC


• The ignition is ON or the engine is running.
• The DTCs run continuously when the above conditions are met.
 Conditions for Setting the DTC

P0403

The ECM detects an open circuit when the EGR is commanded ON.

P0489

The ECM detects a short to ground when the EGR is commanded ON.

P0490

The ECM detects a short to voltage when the EGR is commanded ON.

  Action Taken When the DTC Sets

DTCs P0403, P0489 and P0490 are Type B DTCs.

 Conditions for Clearing the DTC

DTCs P0403, P0489 and P0490 are Type B DTCs.

 Reference Information

 Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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. Ignition ON, observe the DTC information with a scan tool. Verify that no other DTCs are set.
2. If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
3. DTCs P0403, P0489 or P0490 should not set.
4. 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. Ignition OFF, disconnect the harness connector at the Q14 Exhaust Gas Recirculation (EGR) Valve and K20 Engine Control Module.
2. Test for greater than 500 kΩ between the low reference circuit terminal 2 and ground.
3. If less than the specified range, test the low reference circuit for a short to ground.
4. Test for less than 5 Ω between the low reference circuit terminal 2 at the Q14 Exhaust Gas Recirculation (EGR) Valve and the low reference circuit terminal listed below at the K20 Engine Control Module.
• LCD/LBX/LBS Terminal 49 X1
• LBY Terminal 95 X1
5. If greater than the specified range, test the low reference circuit for an open/high resistance.
6. Connect the harness connector X1 to the K20 Engine Control Module.
7. Ignition ON, test for greater than 11 V between the control circuit terminal 6 and ground.
8. If less than the specified range, test the control circuit for a short to ground or an open/high resistance.
9. If all circuits test normal, test or replace the Q14 Exhaust Gas Recirculation (EGR) Valve.
10. Connect the harness connector to the Q14 Exhaust Gas Recirculation (EGR) Valve. Clear the DTC information and operate the vehicle within the conditions for running the DTC.
11. If the DTC resets, replace the K20 Engine Control Module.
 Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Exhaust Gas Recirculation Valve Replacement

• Engine Control Module Replacement for ECM replacement, setup, and programming