P1400

A1: MEASURE THE VREF VOLTAGE AT DPFE SENSOR VEHICLE HARNESS CONNECTOR
1. Disconnect the DPFE sensor electrical connector.
2. Switch the ignition to the RUN position.
3. Measure the voltage between the DPFE sensor electrical connector PI14 pin 1, (YU) and pin 2, (NU).

Is the VREF voltage between 4.0 and 6.0 Volts

Yes
Go to A2

No
Go to A4


A2: CHECK DPFE SIGNAL CIRCUIT FOR SHORTS TO GROUND
1. Switch the ignition to the OFF position.
2. Disconnect the engine harness electrical connector at the PCM.
3. Measure the DPFE signal wire resistance between the DPFE sensor electrical connector PI14 pin 3, (WU) and GROUND.

Is the resistance less than 0.5 Ohms?

Yes
REPAIR the DPFE signal circuit between the PCM harness electrical connector PI1 pin 41, (WU) and the DPFE sensor electrical connector PI14 pin 3, (WU). CLEAR DTC. TEST the system for normal operation.

No
Go to A3


A3: CHECK FOR CONTINUITY BETWEEN THE DPFE SENSOR ELECTRICAL CONNECTOR AND THE PCM HARNESS ELECTRICAL CONNECTOR
1. Measure the resistance between the DPFE signal circuit electrical connector PI14 pin 3, (WU) and the PCM harness electrical connector PI1 pin 41, (WU). CLEAR DTC. TEST the system for normal operation.

Is the resistance less than 0.5 Ohms?

Yes
INSTALL a new DPFE sensor CLEAR DTC. TEST the system for normal operation.

No
REPAIR the DPFE signal circuit between the DPFE sensor electrical connector PI14 pin 3, (WU) and the PCM harness electrical connector PI1 pin 41, (WU). CLEAR DTC. TEST the system for normal operation.


A4: CHECK THE VREF CIRCUIT CONTINUITY BETWEEN THE DPFE SENSOR ELECTRICAL CONNECTOR AND THE PCM HARNESS ELECTRICAL CONNECTOR
1. Switch the ignition to the OFF position.
2. Disconnect the throttle position sensor electrical connector.
3. Disconnect the fuel injector pressure sensor electrical connector.
4. Disconnect the PCM electrical connector, PI1.
5. Measure the resistance between the DPFE sensor electrical connector PI14 pin 1, (YU) and the PCM harness electrical connector PI1 pin 20, (Y). CLEAR DTC. TEST the system for normal operation.

Is the resistance less than 0.5 Ohms?

Yes
Go to A5

No
REPAIR the DPFE VREF circuit between the DPFE sensor electrical connector PI14 pin 1, (YU) and the PCM harness electrical connector PI1 pin 20, (Y). CLEAR DTC. TEST the system for normal operation.


A5: CHECK THE VREF CIRCUIT BETWEEN THE DPFE SENSOR ELECTRICAL CONNECTOR AND THE PCM HARNESS ELECTRICAL CONNECTOR FOR SHORT TO GROUND
1. Measure the resistance between the DPFE VREF circuit, at the DPFE sensor electrical connector PI14 pin1, (YU) and GROUND.

Is the resistance less than 0.5 Ohms?

Yes
REPAIR the DPFE VREF circuit between the DPFE sensor electrical connector PI14 pin 1, (YU) and the PCM harness electrical connector PI1 pin 20, (Y). CLEAR DTC. TEST the system for normal operation.

No
Go to A6


A6: CHECK THE DPFE CIRCUIT FOR GROUND SUPPLY
1. Reconnect the PCM electrical connector PI1.
2. Switch the ignition to the RUN position.
3. Measure the resistance between the DPFE GROUND electrical connector PI14 pin 2, (NU) and GROUND.

Is the resistance less than 0.5 Ohms?

Yes
INSTALL a new DPFE sensor. CLEAR DTC. TEST the system for normal operation.

No
REPAIR the DPFE GROUND circuit between the DPFE sensor electrical connector PI14 pin 2, (NU) and GROUND. CLEAR DTC. TEST the system for normal operation.