Circuit/System Testing
- With the ignition ON and the engine OFF, observe the DTC information on the scan tool.
- Disconnect the EGR harness connector and measure the EGR 5-volt reference circuit for 4.8-5.2 volts.
- If the voltage is less than 4.8 volts, test the EGR valve 5-volt reference circuit for an open, high resistance, a short to ground or a short to the EGR low control circuit.
- If the voltage is more than 5.2 volts, test the EGR valve 5-volt reference circuit for a short to voltage or a short to the EGR high control circuit.
- Using a 3-amp fused jumper wire, connect the EGR 5-volt reference circuit to the EGR position signal circuit and observe the EGR Position Sensor parameter for more than 4.9 volts.
- If the EGR Position Sensor parameter is less than 4.9 volts, test the EGR position signal circuit for an open or high resistance or a short to ground.
- Using a 3-amp fused jumper wire, connect the EGR high control circuit to the EGR low control circuit at the EGR harness connector. Command the EGR valve to 10 percent while monitoring the EGR Position Sensor parameter. The EGR Position Sensor parameter should remain at 0 percent.
- If the EGR Position Sensor parameter is more than 0 percent, test the EGR position signal circuit for a short to the EGR high control circuit.
- If all circuits test OK, replace the EGR valve.