P0406

Steps 1 - 7:

Steps 8 - 14:

Steps 15 - 16:

DTC P0406 EGR High Voltage




Circuit Description
The powertrain control module (PCM} monitors the EGR valve pintle position input to ensure that the valve responds properly to command from the PCM. If current pintle position voltage indicates more than 4.5 V and last more than 10 seconds, then the PCM will set DTC P0406.

Conditions for Setting the DTC
- Ignition voltage is between 11 and 16 volts.
- EGR pintle position output voltage is more than 4.8 volt and last more than 10 sec.

Action Taken When the DTC Sets
- The PCM will illuminate the malfunction indicator lamp (MIL) as soon as failure detected.
- The PCM will store conditions which were present when the DTC was set as Freeze Frame and in 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 P0402 will clear after 40 consecutive warm-up cycles have occurred without a fault.
- DTC P0404 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:
- Poor connection or damaged harness - Inspect the wiring harness for damage. If the harness appears to be OK, observe the EGR actuator position display on the scan tool while moving connectors and wiring harnesses related to EGR valve. A change in the display will indicate the location of the fault.
- Operate the vehicle in second or third gear to remain in the DTC P0420 test conditions described in Conditions for Setting the DTC as much as possible. If you must stop the vehicle, maintain the warm catalyst criteria as follows:
- Place the vehicle in Park or Neutral
- Hold part throttle to maintain a mass air flow reading of over 15 g/second for the duration of the stop.