EGR - Closed Position Error

CLOSED POSITION ERROR
The linear EGR system consists of a linear EGR valve, the PCM and its associated wiring. The EGR valve solenoid is controlled directly by the PCM when Certain conditions have been met. The PCM contains a diode feedback circuit which dissipates energy when the valve is cycled Off. When the PCM commands the EGR valve closed, a closed valve position value is learned. If the PCM commands the valve closed and the actual feedback value does not match the learned value, DTC P01404 will set.

DTC PARAMETERS

DTC P1404 will set when the actual dosed value does not match the learned closed value within 20 seconds if:


^ RPM is below 5000 and the actual vs learned is greater than 0.2 volts, or


^ RPM is above 5000 and the actual vs learned is greater than 0.4 volts.


IMPORTANT:
If DTCs P0404 or P0405 are also set, begin diagnosis with these DTCs first. Do not clear codes until diagnosis is completed.


IMPORTANT:
When the PCM recognizes that the parameters for setting P1404 have been set, the diagnostic software waits until the EGR cycles open 50% or greater four times and then retests. If after the four cycles the actual vs learned is not within the parameters, the DTC will be stored and the MIL (SERVICE ENGINE SOON) will be commanded on.

IMPORTANT:
When this DTC sets, functions will be disabled. When repairs are complete, codes must be cleared and ignition keyed off for at least 10 seconds to allow proper operation.


DIAGNOSTIC AIDS

^ Check for backed out or damaged terminals.

^ Check for a stuck open EGR pintle. Inspect EGR pintle valve bore for carbon or debris and remove. Verify that the pintle moves freely and the return spring forces the pintle closed.

^ An open in circuit 452 will result in P1404.

^ A short to ground in circuit 697 will result in a severe rough idle and driveability complaint and set a P1404.

^ Check for backed out, damaged, poor terminal tightness or an intermittent open in circuits 416 or 1456.