P0403

DTC P0403

CIRCUIT DESCRIPTION




The DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit diagnostic detects faults in the EGR valve electrical circuit. The powertrain control module (PCM) controls the EGR valve with a solid state device called a driver. The driver supplies the EGR solenoid with 12 volts that is pulse width modulated (PWM) through the EGR solenoid high control circuit. A ground path is provided by the PCM through the EGR solenoid low control circuit. The driver has the ability to detect an electrical malfunction on the EGR solenoid control circuits. If the PCM determines that the driver has detected an electrical malfunction on one of these circuits, this DTC sets.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC.
DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit

CONDITIONS FOR RUNNING THE DTC
- DTC P0030, P0050, P0097, P0098, P0107, P0108, P0117, P0118, P0135, P0155, P0335, P0336, P0401, P0404, P0406, P0641, P0651, P1128, P1129, P2238, P2239, P2241, P2242, P2243, P2245, P2247, P2249, P2252, P2253, P2255, P2256, P2413, P2414, P2415, P2630, and P2631 are not set.
- The engine is running.
- The EGR is operating between 2-98 percent duty cycle.
- DTC P0403 runs continuously once the above conditions have been met.

CONDITIONS FOR SETTING THE DTC
- The PCM detects an electrical malfunction in the EGR solenoid control circuit.
- The above condition is present for more than 5 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.

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.
- Clear the MIL and the DTC with a scan tool.

TEST DESCRIPTION

Steps 1-11:

Steps 12-14:

The number below refers to the step number on the diagnostic table.
5. This step checks for an open in the EGR solenoid control circuit. The PCM provides a 12 volt bias signal on the solenoid control circuit that is pulled low when the solenoid is OK and has a good ground.
6. This step tests whether the PCM is actually commanding ON the EGR valve.
12. After replacing the PCM a new minimum throttle position and idle speed must be established.