P0405

Wiring Diagram:

EGR Position Sensor Circuit Low Voltage:

P0405- EGR POSITION SENSOR CIRCUIT LOW VOLTAGE
The exhaust gas recirculation(EGR) value consists of a pintle valve which moves by the use of an internal solenoid and an internal position sensor (potentiometer) used to determine pintle valve position. The ECM controls the Solenoid by supplying it ground whenever exhaust gas needs to be recirculated into the intake manifold. The ECM monitors the EGR solenoid and position sensor circuit for correct voltage levels at certain times. Normal EGR sensor voltages range from 0.5-1.0 volts at a 0% commanded duty cycle up to 4.24.7 volts at a 100% commanded duty cycle. DTC P0405 sets when the EGR sensor signal voltage at the ECM is below the calibrated voltage value.

DTC PARAMETERS
DTC P0405 will set it EGR sensor signal voltage is less than 0.14 volts when:
^ Condition exists for longer than 1 second
^ Engine is running
^ No system voltage DTCs have been set

DTC P0405 diagnostic runs continuously with engine running.

P0405 is a type B DTC

DIAGNOSTIC AIDS
To locate an intermittent problem, use Scan tool to monitor EGR SENSOR voltage with ignition On, engine Off.

Wiggling wires while monitoring EGR SENSOR may locate the area where an open or short to ground in wiring may exist.

IMPORTANT: The EGR valve will not move until a 40% or greater duty cycle is commanded.

An intermittent open in the EGR sensor can set this DTC. Using Scan tool monitor EGR SENSOR while commanding EGR SOLENOID incrementally from 0 to 100% duty cycle.

Circuit 416 (CMP/EGR/MAF/MAP sensor), circuit 2709 (AC pressure/fuel tank pressure sensor) and circuit 1164 (APP sensor 1) share the same 5 volt reference supply (5 volt Ref-A).

The CMP/ECT/IAT/EGR/MAF/MAP/TP1/TP2 sensors share the same sensor return circuit 652.

IMPORTANT: When DTC P0405 sets, some EGR functions will be disabled for the remainder of the ignition cycle. When repairs are complete, DTCs must be cleared and ignition keyed Off for 10 seconds to allow proper EGR operation.