P0403-EGR SOLENOID CIRCUIT OPEN





For a complete wiring diagram Refer to Section 8W

Theory of Operation


The EGR Solenoid is a two-wire electrically operated vacuum solenoid used to control the vacuum supply to the EGR Solenoid. The Solenoid receives 12 volts from the ECM/ASD relay and a pulse-width modulated ground signal from the ECM. The solenoid contains 2 vacuum ports. Vacuum from the vacuum pump system is supplied to one of the ports. The other port is connected to the EGR Solenoid. With the solenoid de-energized (off) the vacuum supply is blocked within the solenoid, prohibiting vacuum from reaching the EGR Solenoid. When the ECM energizes (grounds) the solenoid, the vacuum supply is applied to the EGR Solenoid causing the EGR Solenoid to open.



Possible Causes
INTERMITTENT DTC
(K35) EGR SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
(K35) EGR SOLENOID CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
(F344) FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
EGR SOLENOID
ENGINE CONTROL MODULE (ECM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)



Diagnostic Test

1. DTC IS ACTIVE

Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
With the scan tool, actuate the Exhaust Gas Recirc Positioner.
Monitor the scan tool for at least two minutes.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

2. (K35) EGR SOLENOID CONTROL CIRCUIT SHORTED TO GROUND



Turn the ignition off.
Disconnect the EGR Solenoid harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance between ground and the (K35) EGR Solenoid Control circuit in the EGR Solenoid harness connector.

Is the resistance above 1000 ohms?

Yes


No

3. (K35) EGR SOLENOID CONTROL CIRCUIT OPEN OR HIGH RESISTANCE



Measure the resistance of the (K35) EGR Solenoid Control circuit between the EGR Solenoid harness connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes


No

4. (F344) FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE



Connect the Engine Control Module (ECM) connector.
Turn the ignition on.
Using a 12 volt test light connected to ground, check the (F344) Fused ASD Relay Output circuit at the EGR Solenoid harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.



Is the test light illuminated and bright?

Yes


No

5. EGR SOLENOID



With the scan tool, actuate the Exhaust Gas Recirc Positioner to 100%.
Using a 12 volt test light connected to 12 volts, check the (K35) EGR Solenoid Control circuit in the EGR Solenoid harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.


NOTE: The circuit will remain actuated by the controller for 30 seconds. Be certain the actuation is active when checking the circuit.



Is the test light illuminated and bright?

Yes


No

6. ENGINE CONTROL MODULE (ECM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the EGR Solenoid and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


No