P1406

DIAGNOSTIC TROUBLE CODE (DTC) P1406
EGR VALVE PINTLE POSITION CIRCUIT

Circuit Description
The powertrain control module (PCM) monitors the EGR valve pintle position input to ensure that the valve responds properly to commands from the PCM, and to detect a fault if the pintle position sensor and control circuits are open or shorted. If the PCM detects a pintle position signal voltage outside the normal range of the pintle position sensor, or a signal voltage that is not within a tolerance considered acceptable for proper EGR system operation, the PCM will set DTC P1406.

Conditions for Setting the DTC
- Ignition voltage is between 11 and 16 volts.
- EGR feedback is less than 0.10 volt at any time for more than 5 seconds.

OR

- The desired EGR position is commanded to 0% and EGR feedback is 0.20 volt greater or less than the EGR closed valve pintle position for more than 5 seconds.

OR

- The EGR position is not changing more than 3% in 5 seconds.
- The desired EGR position is commanded above 0%, and the actual EGR position is 15% greater or less than the desired EGR position for more than 5 seconds.

Action Taken When the DTC Sets
- The PCM will illuminate the malfunction indicator lamp (MIL) after the second consecutive trip in which the fault is detected.
- The PCM will store conditions which were present when the DTC was set as Freeze Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC
- The PCM will turn the MIL "OFF" on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
- A history DTC P1406 will clear after 40 consecutive warm~up cycles have occurred without a fault.
- DTC P1406 can be cleared by using the scan tool "Clear Info" function or by disconnecting the PCM battery feed.

Diagnostic Aids
Check for the following conditions:
- Excessive deposits on EGR valve pintle or seat - Check for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.
- Poor connection or damaged harness - Inspect the wiring harness for damage. If the harness appears to be OK, observe the EGR actual po5ition display on the scan tool while moving connectors and wiring harnesses related to the EGR valve. A change in the display will indicate the location of the fault.
Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Notice: If the EGR valve shows signs of excessive heat, check the exhaust system for blockage (possibly a plugged catalytic converter) using the "Restricted Exhaust System Check."

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Chart.
6. If there is a problem with the ignition supply for the EGR valve, the ignition module and ECM main relay could also be affected since they use the same fuse. Also, a MAF sensor DTC or a canister purge driver module DTC may be set.
8. When testing the control wire to the PCM, make sure you test the yellow wire instead of the yellow with red tracer. The exposed part of the wire is very short, and the tracer may be difficult to notice.
16. The EGR valve tested OK electrically, but it may be defective due to coking or internal mechanical failure.
23. If the PCM is being replaced due to a faulty 5 volt reference, another indication of this would be a TPS DTC because that sensor uses the same PCM pin for a 5 volt reference.
27. If the PCM is being replaced due to a faulty sensor ground, another indication of this would be an IAT or TPS DTC because both of those sensors use the same PCM pin for a sensor ground.