P1406

DTC P1406 EGR Valve Pintle Position Circuit (1 Of 4):

DTC P1406 EGR Valve Pintle Position Circuit (2 Of 4):

DTC P1406 EGR Valve Pintle Position Circuit (3 Of 4):

DTC P1406 EGR Valve Pintle Position Circuit (4 Of 4):

EGR System:

CIRCUIT DESCRIPTION
The Vehicle Control Module (VCM) constantly monitors the linear EGR valve pintle position sensor to ensure that the valve is responding properly to commands from the VCM. The DTC P1406 is a type A DTC.

CONDITIONS FOR SETTING THE DTC
The following conditions will set the DTC:

^ EGR pintle position signal indicates a voltage out of the normal range of the pintle position sensor, or a signal that is 10% greater or less than the VCM commanded position
^ Ignition voltage greater than 9 volts

ACTION TAKEN WHEN DTC SETS
It a current DTC P1406 sets during 2 consecutive test cycles, the VCM turns on the Malfunction Indicator Lamp (MIL).

CONDITIONS FOR CLEARING THE MIL/DTC
The VCM turns the MIL off after 3 consecutive driving trips without a fault condition present. A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 40°F from the start-up coolant temperature and the engine coolant temperature exceeds 160°F during that same ignition cycle) or the scan tool clearing feature has been used.

DIAGNOSTIC AIDS
A poor connection or rubbed-through wire insulation may cause an intermittent. Check for the following conditions:

^ Poor connection or damaged harness - Inspect VCM harness connectors for backed out terminals EGR Control signal circuit, 5 V reference circuit, EGR sensor ground circuit, or Pintle position circuit for the following items:

^ Improper mating.
^ Broken locks.
^ Improperly formed or damaged terminals.
^ Poor terminal to wire connection.
^ Damaged harness.

Intermittent test - If connections and harness check OK, monitor a digital voltmeter connected between affected terminals and ground while moving related connectors and wiring harness. If the failure is induced, the voltage reading will change.

TEST DESCRIPTION
The numbers below refer to the step umbers on the diagnostic table.

2. Checks for an EGR valve sticking partially open or an incorrect pintle position sensor feedback signal.
3. Ensures that the VCM is capable of controlling EGR pintle position and is reading the pintle position feedback signal properly.
4. Checks the EGR valve driver in the VCM and the EGR Control signal circuit.
5. The checks for an incorrect EGR pintle position sensor input signal. This test verifies a 5 volt reference at the EGR valve.