For 1990-2009 cars

### Circuit Description

The exhaust gas recirculation (EGR) value consists of a pintle valve that moves by the use of an internal solenoid and an internal position sensor, potentiometer, which used to determine pintle valve position. The engine control module (ECM) controls the solenoid by supplying it ground whenever exhaust gas needs to be recirculated into the intake manifold. When the solenoid is commanded OFF, circuit not grounded, the voltage level at the ECM should be high, ignition voltage. When the solenoid is commanded ON, circuit grounded, the voltage level at the ECM should be low. The ECM EGR solenoid feedback circuit uses a pull-up voltage, 2.6-4.6 volts, which allows the ECM to individually differentiate between an open, short to ground, or short to voltage. DTC P1403 will set if the ECM detects higher than normal feedback voltage when the EGR solenoid is commanded ON with the engine running.

### Conditions for Setting the DTC

DTC P1403 will set if EGR solenoid feedback voltage is greater than 4.6 volts when the EGR solenoid is commanded ON when:

• | The condition exists for longer than 0.5 seconds.

• | The engine speed is greater than 40 RPM.

• | The battery is between 7.5-15 volts.

DTC P1405 diagnostic runs continuously once the above conditions have been met.

DTC P1405 is a type B DTC.

### Diagnostic Aids

To locate an intermittent problem, use the scan tool to command EGR SOLENOID ON at a 100 percent duty cycle with the engine running, while using the scan tool to monitor EGR SENSOR. The EGR SENSOR voltage should remain between 4-4.5 volts. Wiggling the wires while watching for a drop in EGR SENSOR voltage may locate a shorted solenoid or the area where a short to voltage in the wiring may exist.

If either circuit 251 is shorted to voltage, DTC P1405 will set.

The EGR solenoid resistance is 7-11 ohms.