P0403

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) monitors the Exhaust Gas Recirculation (EGR) valve pintle position input in order to ensure that the valve responds properly to the commands from the PCM. The linear EGR valve is controlled by using an ignition positive driver and ground circuit within the PCM. The driver can detect an electrical malfunction in the ignition positive or ground circuit. If an electrical malfunction occurs, the driver signals the PCM to set this Diagnostic Trouble Code (DTC).

CONDITIONS FOR RUNNING THE DTC
The engine is cranking or running.

The system voltage is between 10-16 volts.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects an electrical malfunction in the control circuit for the EGR valve.
^ The condition is present for more than 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
^ The PCM disables the EGR valve for the ignition cycle.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC "Last Test Failed" clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

TEST DESCRIPTION

Steps 1-4:

Steps 5-15:

The numbers below refer to the step numbers on the diagnostic table.
4. When using the scan tool to increment the EGR valve, increment the valve to 10 percent then to 0 percent. Repeat this process in order to see if the test lamp turns ON then OFF. If the test lamp stays ON after the valve is commanded to 0 percent the EGR solenoid high control circuit is shorted to voltage.
5. This step tests for an open in the ground circuit to the solenoid.
6. This step tests if voltage is constantly being applied to the solenoid.