DTC P1400 [YF (2.0L Zetec)]

id0102d0824900

DTC P1400

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. 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
• Damaged D.P.F. EGR sensor
• Short to GND in wiring between D.P.F. EGR sensor terminal 1 and PCM terminal 90
• Damaged PCM

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the 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 the next step.
No
Go to the next step.
3
INDETIFY TRIGGER DTC FOR FREEZE FRAME DATA
• Is DTC P1400 on FREEZE FRAME DATA?
Yes
Go to the 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 V?
Yes
Go to the next step.
No
Inspect the constant voltage, then go to Step 9.
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-2.
• 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 the next step.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.