DTC Advanced Diagnostics: P049D (3.5L Engine)
DTC P049D: Exhaust Gas Recirculation (EGR) Control Position Exceeded Learning Limit
General Description
The powertrain control module (PCM) controls the exhaust gas recirculation (EGR) valve opening. The system includes the EGR actuator, the EGR valve, the EGR valve position sensor, and the PCM. The EGR valve position sensor is a semiconductor type, and it is attached to the EGR valve and shaft to determine EGR valve position. The EGR valve position signal from the EGR valve position sensor is transmitted to the PCM for target position feedback control. The PCM transmits a signal to the throttle actuator and moves the EGR valve to the fully closed position to register the EGR valve fully closed position when the vehicle is turned to the ON mode or during EGR operation is not in progress. If the registered value is out of predetermined range after the fully closed position registration is completed, the PCM detects a malfunction in the EGR system and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | - |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | |
|---|---|
| Vehicle | ON mode |
Malfunction Threshold
The registered value of the EGR valve fully closed position is 2.36 mm (0.0930 in) or more, -2.11 mm (-0.0830 in) or less.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- EGR valve E_EGR line open
- EGR valve E-EGR ground line open
- EGR valve position sensor failure
- EGR valve failure
- PCM internal circuit failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.