DTC P1400 [AJ (3.0L Duratec)]

id0102a4824900

DTC P01400

Differential Pressure Feedback (D.P.F.) EGR sensor circuit low voltage detected

DETECTION CONDITION

• The PCM monitors the D.P.F. EGR sensor output voltage at PCM terminal 65 (R.H.D.) /E-44 (L.H.D.). If the PCM detects that average D.P.F. EGR sensor voltage drops to a voltage less than the minimum calibrated value, the PCM determines that the D.P.F. EGR sensor circuit low voltage.

POSSIBLE CAUSE

• Short to GND in wiring between D.P.F. EGR sensor terminal 3 and PCM terminal 65 (R.H.D.) /E-44 (L.H.D.)
• Damaged D.P.F. EGR sensor
• Short to GND in wiring between D.P.F. EGR sensor terminal 1 and PCM terminal 90 (R.H.D.) /E-40 (L.H.D.)
• Damaged PCM

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
Yes
Go to next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to next step.
2
VERIFY REPAIR INFORMATION AVAILABILITY
• Verify related service repair information availability.
• Is any related repair information available?
Yes
Perform repair or diagnosis according to the available repair information.
• If the vehicle is not repaired, go to next step.
No
Go to next step.
3
INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA
• Is DTC P1400 on FREEZE FRAME DATA?
Yes
Go to next step.
No
Go to FREEZE FRAME DATA DTC inspection.
4
DETERMINE PRESENT DPFEGR PID VOLTAGE
• Turn the ignition switch to ON.
• Access DPFEGR PID.
• Is DPFEGR PID voltage less than 0.2 v?
Yes
Go to the next step.
No
Go to Step 8.
5
ATTEMPT TO INDUCE OPPOSITE D.P.F. EGR SENSOR VOLTAGE
• Disconnect D.P.F. EGR sensor.
• Turn the ignition switch to ON.
• Is DPFEGR PID value 4.0-6.0 V?
Yes
Replace D.P.F. EGR sensor, then go to Step 9.
No
Go to the next step.
6
CHECK VREF AND SIG RTN CIRCUITS FOR OPEN IN HARNESS TO D.P.F EGR SENSOR
• Measure voltage between VREF and SIG RTN circuits at the D.P.F. EGR sensor harness connector.
• Is VREF voltage 4.0-6.0 VV?
Yes
Go to the next step.
No
Go to symptom troubleshooting "No.27 CONSTANT VOLTAGE" diagnostic procedure.
7
CHECK D.P.F.EGR CIRCUIT FOR SHORT TO GROUND AND SIG RTN IN HARNESS
Note
• Refer to the PCM connector pin numbers in the beginning of this pinpoint test.
• Disconnect WDS or equivalent from DLC.
• Disconnect PCM.
• Measure resistance between D.P.F.EGR and SIG RTN circuits at the PCM harness connector.
• Measure resistance between D.P.F.EGR circuits at the PCM harness connector and battery negative post.
• Is each resistance greater than 10,000 ohms?
Yes
Replace PCM, then go to Step 9.
No
Repair short to ground or SIG RTN circuit, then go to Step 9.
8
PERFORM WIGGLE TEST ON D.P.F. EGR SENSOR AND CIRCUIT WHILE MONITORING DPFEGR PID FOR A SUDDEN CHANGE
• While monitoring DPFEGR PID, top on the D.P.F.EGR sensor and wiggle the wiring while looking for a sudden change in value as an indication of an intermittent.
• Is intermittent fault found?
Yes
Repair or replace malfunctioning part, then go to the next step.
No
Unable to duplication or identify fault at this time.
Go to the next step.
9
VERIFY TROUBLESHOOTING OF DTC P1400 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Perform KOEO/KOER self test.
• Is the PENDING CODE same DTC present?
Yes
Replace PCM, then go to next step.
No
Go to the next step.
10
VERIFY AFTER SERVICE PRECAUTION
• Perform "AFTER SERVICE PRECAUTION".
• Is there any DTC present?
Yes
Go to applicable DTC inspection.
No
Troubleshooting completed.