P0405

Schematic:

CIRCUIT DESCRIPTION

The Powertrain Control Module (PCM) monitors the Exhaust Gas Recirculation (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 circuit is open or shorted. If the PCM detects an excessively low EGR feedback signal voltage, DTC P0405 will set.

CONDITIONS FOR RUNNING THE DTC
System voltage is greater than 10 volts.

CONDITIONS FOR SETTING THE DTC
^ EGR feedback is less than 0.14 volt at any time.
^ The condition is present for more than 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
^ If the misfire is determined to be catalyst damaging, the PCM will flash the MIL.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
^ The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using a scan tool.

DIAGNOSTIC AIDS
^ A faulty connection at the PCM or the EGR valve-Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connections. Use a corresponding mating terminal to test for proper terminal tension.
^ Inspect the wiring harness for damage. If the harness appears to be OK, connect a Digital Multimeter (DMM) and check the circuit continuity while moving the connectors and the wiring harnesses related to the EGR valve. A change in the DMM display indicates the location of the malfunction.


TEST DESCRIPTION

Steps 1 - 10:

Steps 11 - 19:

The numbers below refer to the step numbers on the diagnostic table.
2. Verifies that the malfunction is present.
3. If DTC P0405 will only set under certain conditions, the malfunction may be intermittent. If an intermittent wiring problem is not present, check for a faulty connection at the PCM or the EGR valve.
18. This vehicle is equipped with a PCM which utilizes an electrically Erasable Programmable Read-only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.