P0403

Circuit Description

The PCM monitors the EGR valve pintle position input to ensure that the valve responds property to commands from the PCM. The Linear EGR valve is controlled by using an ignition positive driver and ground circuit within the PCM. The driver has the ability to detect an electrical malfunction in the ignition positive or ground circuit. If an electrical malfunction occurs, the driver signals the PCM to set DTC P0403.

Conditions for Running the DTC

^ No TP, VSS, Misfire, IAT, MAP, Idle Speed, Fuel Injector, ECT, CKP, or MAF sensor DTCs set.
^ System voltage is between 10 volts and 16 volts.

Conditions for Setting the DTC

^ The PCM detects an electrical malfunction in the control circuit for the EGR valve.
^ The above condition is present for longer than 20 seconds.

Action Taken When the DTC Sets

^ The PCM will illuminate the MIL during the second consecutive trip in which the diagnostic test has been run and failed.
^ The PCM will disable EGR for the ignition cycle.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

Diagnostic Aids

^ Poor connection at PCM or EGR Valve.
Inspect harness connectors for backed out terminals, improper mating, broken locks improperly formed or damaged terminals, and poor terminal to wore connection.
^ Damaged harness.
Inspect the wiring harness for damage. If the harness appears to be OK, with a J 39200 Digital Multimeter, check circuit continuity while moving connectors and wiring harnesses related to the EGR valve. A change in the display will indicate the location of the malfunction.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

2. Listen for an audible click when the solenoid operates. Command the EGR between 0% to 10%. Repeat the commands as necessary.
3. Verifies that the PCM is providing voltage to the solenoid.
4. Tests for an open in the ground circuit to the solenoid.
5. Tests if voltage is constantly being applied to the solenoid.
12. The PCM utilizes Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.