System Test

Linear EGR System Check:

Linear EGR System:

Circuit Description:
To control 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 exhaust gasses to pass through the valve. The control module control of the EGR is based on the following inputs:

- Engine coolant temperature - above 25° C.
- TPS - "OFF" idle.
- MAP
- BARO
- Park/Neutral Position.
- Pintle Position Sensor.

If DTC 32 is stored, use that chart first. This chart is used for faulty valve, plugged EGR passages, or improper wiring connections.

Chart Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. 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
2. Checks the pintle's ability to be manually commanded to the desired position.
3. Checks the electrical circuit of the EGR valve and connecting components.
4. Checks for plugged EGR passages or a faulty EGR valve.