P0404

DTC P0404






CIRCUIT DESCRIPTION
This diagnostic monitors the exhaust gas recirculation (EGR) valve position. The position sensor is mounted within the EGR valve and is part of the EGR valve assembly. A 5-volt reference circuit, low reference circuit, and a signal circuit are used by the powertrain control module (PCM) to determine the EGR valve position. The PCM compares the EGR Position Sensor parameter with the desired EGR Position parameter when the valve is commanded open or closed. If the PCM detects a calibrated difference between the EGR Position Sensor parameter and desired EGR Position parameter for a calibrated amount of time, this DTC sets.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance

CONDITIONS FOR RUNNING THE DTC
- DTC P0030, P0050, P0107, P0108, P0112, P0113, P0117, P0118, P0135, P0155, P0335, P0336, P0401, P0403, P0406, P0641, P0651, P1128, P1129, P2413, P2414, and P2415 are not set.
- The battery voltage is at least 10.5 volts.
- The EGR valve is commanded open to at least 0.25 mm (0.010 in).
- Engine speed is less than 4,000 RPM.
- DTC P0404 runs once per drive cycle once the above conditions have been met.

CONDITIONS FOR SETTING THE DTC
- The difference between the desired EGR position and the measured EGR position, as determined by the EGR position sensor, is more than 1.020 mm (0.041 in).
- 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) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the 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.

DIAGNOSTIC AIDS
- Inspect for excessive deposits on the EGR pintle or seat. Inspect for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.
- If the condition is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Step 1 - Step 10:

Step 11 - Step 21:

The numbers below refer to the step numbers on the diagnostic table.
5. This step tests for high resistance in reference voltage circuit. If the test lamp does not illuminates at all, there is excessive resistance in the 5-volt reference circuit or low reference ground circuit.
8. This step tests for high resistance in the EGR solenoid control circuit and ground circuits. 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. If the circuit resistance is OK, the DMM should measure ignition voltage.
19. After replacing the PCM a new minimum throttle position and idle speed must be established.