System Check - EGR

Diagnostic Chart:

Wiring Diagram:

Circuit Description
In order to control the Exhaust Gas Recirculation (EGR), the control module operates the linear EGR valve. The linear EGR valve is a small motor with a pintle that is normally closed. By providing a ground path, the control module will open the pintle and allow the exhaust gasses to pass through the valve. The control module of the EGR is based on the following inputs:

^ The engine coolant temperature above 25°C.
^ The TP OFF idle.
^ MAP.
^ BARO.
^ Park/neutral position.
^ Pintle position sensor.

If DTC P0401 or P1406 is stored, refer to the applicable DTC table. This chart is used for a faulty valve, plugged EGR passages, or improper wiring connections.

Test Description
The numbers below refer to the step numbers in the diagnostic table.

2. At idle, the EGR valve should not be open greater than 3%. A faulty park/neutral position Trans Range (TR) position pressure switch or the EGR valve stuck open will allow exhaust gasses to enter the combustion chamber and create a rough idle condition.

3. This step checks the ability of the pintle to be manually commanded to the desired positions.

11. This step checks the electrical circuit of the EGR valve and connecting components.

13. This step checks for plugged EGR passages or a faulty EGR valve.