Circuit Description
The PCM controls the movement of the valve using the EGR control circuit. The PCM monitors the pintle position signal to make sure that the valve responds to the commands from the PCM. With the key turned ON, the PCM learns the EGR closed valve pintle position. When the PCM commands the valve closed, the PCM looks at the difference between the learned closed valve pintle position, and the actual EGR position. If a large difference is present for a certain length of time, the PCM records an error. After the PCM records a calibrated number of consecutive errors, DTC P1404 will set.
Conditions for Running the DTC
| • | No TP sensor, VSS, Misfire, IAT sensor, MAP sensor, Idle Speed, Fuel Injector, ECT sensor, CKP sensors, or MAF sensor DTCs are set |
| • | The system voltage is between 10-16 volts. |
| • | The EGR is enabled. |
| • | After an initial test failure a 60 percent valve opening must be achieved and maintained for at least 5 seconds. |
Conditions for Setting the DTC
| • | The PCM detects a 25 percent difference between the learned closed valve position and the actual EGR position. |
| • | The PCM detects the error for at least 4 consecutive tests. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails. |
| • | The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes. |
| • | 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 DTC Information function. |
Diagnostic Aids
If the PCM detects a closed valve error, the PCM delays setting DTC P1404 until the valve opens at least 60 percent for 5 seconds. This allows for the possible self-cleaning of the system to remove deposits/corrosion on the valve shaft, or debris from the valve seat.
If the condition is intermittent, refer to Intermittent Conditions in Symptoms.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 |
Important: If DTC P0403, P0404, and/or P1635 is set, diagnose the applicable DTC first. Refer to Diagnostic Trouble Code (DTC) List/Type . With the engine idling, observe Actual EGR Position display on the scan tool. Is Actual EGR Position at the specified value? | 0% | Go to DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance | |
3 |
Does the scan tool indicate that DTC P1404 failed last test? | -- | Go to DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance | Go to Diagnostic Aids |
