For 1990-2009 cars

### 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 01: Exhaust Gas Recirculation (EGR) Control Circuit Short to Battery
DTC P0403 02: Exhaust Gas Recirculation (EGR) Control Circuit Short to Ground
DTC P0403 04: Exhaust Gas Recirculation (EGR) Control Circuit Open
DTC P0403 54: Exhaust Gas Recirculation (EGR) Control Circuit Temperature High

### Circuit Description

Voltage is provided to the exhaust gas recirculation (EGR) solenoid valve by the ignition 1 voltage circuit through a fuse. Ground is provided to the EGR solenoid 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 solenoid valve to determine if a failure is present.

### Conditions for Running the DTC

• | 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.

### Conditions for Setting the DTC

#### P0403 01

The ECM detects a short to voltage on the control circuit of the EGR solenoid valve.

#### P0403 02

The ECM detects a short to ground on the control circuit of the EGR solenoid valve.

#### P0403 04

The ECM detects an open circuit on the control circuit of the EGR solenoid valve.

#### P0403 54

The ECM detects that the internal output driver is over temperature.

### Action Taken When the DTC Sets

DTC P0403 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0403 is a Type B DTC.

### 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. Engine running, observe the DTC information with a scan tool. DTC P0403 should not set.
2. Engine running, command the EGR solenoid valve to 100 percent. The engine should run rough or stall.
3. 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 EGR solenoid valve.
2. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal 2 and ground.

⇒ | 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.

3. Connect a test lamp between the control circuit terminal 1 and the ignition 1 voltage circuit terminal 2.
4. Command the EGR solenoid valve between 5-95 percent with a scan tool. The test lamp should respond to the scan tool commands.

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 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 K20 ECM.

5. Test for 2.6-4.6 V between the control circuit terminal 1 and ground.

⇒ | If not within the specified range, replace the K20 ECM.

6. If all circuits test normal, test or replace the EGR solenoid valve.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the EGR valve solenoid.
2. Test for 13-18 Ω between the control terminal 1 and the ignition 1 voltage terminal 2.

⇒ | If not within the specified range, replace the EGR valve solenoid.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Exhaust Gas Recirculation Valve Solenoid Replacement

• | Control Module References for ECM replacement, setup, and programming