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 Descriptor
DTC P0403 04: Exhaust Gas Recirculation (EGR) Control Circuit OpenDTC 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 supplied to the EGR valve solenoid. The ECM controls the solenoid 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
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool. Verify that no other DTCs are set.
- DTCs P0403, P0489 or P0490 should not set.
- 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.
| ⇒ | If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the Q14 Exhaust Gas Recirculation (EGR) Valve.
- Test for less than 5 Ω between the ground circuit terminal 2 and ground.
- Connect a test lamp between the control circuit terminal 6 and the ground circuit terminal 2.
- Command the EGR Valve ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, test or replace the Q14 Exhaust Gas Recirculation (EGR) Valve.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM). |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM). |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Engine Control Module Replacement for ECM replacement, setup, and programming |
