DTC P1401 [YF (2.0L Zetec)]

id0102d0825000

DTC P1401

D.P.F. EGR sensor circuit high 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 goes to a voltage less than the maximum calibrated value, the PCM determines that the D.P.F. EGR sensor circuit high voltage.

POSSIBLE CAUSE

• Open circuit in wiring between D.P.F. EGR sensor terminal 3 and PCM terminal 65
• Short to power in wiring between D.P.F. EGR sensor terminal 1 and PCM terminal 90
• Damaged D.P.F. EGR sensor
• Short to power in wiring between D.P.F. EGR sensor terminal 3 and PCM terminal 65
• Open circuit in wiring between D.P.F. EGR sensor terminal 2 and PCM terminal 91
• 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 P1401 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 with WDS or equivalent.
• Is DPFEGR PID voltage greater than 4.0 V?
Yes
Go to the next step.
No
Go to Step 13.
5
CHECK D.P.F. EGR CIRCUIT FOR SHORT TO PWR
• Disconnect D.P.F. EGR sensor.
• Key on, engine off.
• Measure voltage between D.P.F.EGR circuit at the D.P.F. EGR sensor harness connector and chassis ground.
• Is voltage greater than 10.5 V?
Yes
Go to the next step.
No
Go to Step 7.
6
CHECK D.P.F. EGR CIRCUIT FOR SHORT TO PWR IN HARNESS
• Disconnect PCM.
• Turn the ignition switch to ON.
• Measure voltage between D.P.F. EGR circuit at the PCM harness connector and the battery negative post.
• Is voltage greater than 10.5 V?
Yes
Repair short to power supply, then go to Step 14.
No
Replace PCM, then go to Step 14.
7
INDUCE OPPOSITE D.P.F. EGR SENSOR VOLTAGE
• Connect a jumper wire between terminal 2 and 3 at the D.P.F. EGR sensor harness side connector.
Note
• If a scan tool communication concern exists, key off, remove jumper immediately and go to Step 12.
• Access DPFEGR PID.
• Is DPFEGR PID voltage less than 0.05 V?
Yes
Go to the next step.
No
Unable to induce opposite signal.
Go to Step 10.
8
CHECK VREF VOLTAGE TO D.P.F. EGR SENSOR
• Measure voltage between terminal 1 and 2 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 14.
9
CHECK D.P.F. EGR CIRCUIT FOR SHORT TO VREF IN HARNESS
• Disconnect PCM.
• Measure resistance between terminal 1 and 3 at the PCM harness connector.
• Is resistance greater than 10,000 ohms?
Yes
Replace D.P.F. EGR sensor.
No
Repair short to VREF circuit, then go to Step 14.
10
CHECK D.P.F. EGR CIRCUIT FOR OPEN IN HARNESS
• Disconnect PCM.
• Measure resistance of D.P.F. EGR circuit between PCM terminal 65 and D.P.F. EGR sensor terminal 3 at harness side connector.
• Is resistance less than 5.0 ohms?
Yes
Go to the next step.
No
Repair open circuit, then go to Step 14.
11
CHECK SIG RTN CIRCUIT FOR OPEN IN HARNESS
• Measure resistance of SIR RTN circuit between PCM terminal 91 and D.P.F. EGR sensor terminal 65 at harness side connector.
• Is resistance less than 5.0 ohms?
Yes
Replace PCM, then go to Step 14.
No
Repair open circuit, then go to Step 14.
12
CHECK D.P.F. EGR CIRCUIT FOR SHORT TO VREF IN HARNESS
• Disconnect PCM.
• Measure resistance between PCM terminal 65 and 90 at the PCM harness connector.
• Is resistance greater than 10,000 ohms?
Yes
Replace PCM, then go to Step 14.
No
Short to VREF circuit, then go to Step 14.
13
COMPLETE A WIGGLE TEST ON D.P.F. EGR SENSOR AND CIRCUIT WHILE MONITORING DPFEGR PID FOR A SUDDEN CHANGE
• While monitoring DPFEGR PID, tap 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.
14
VERIFY TROUBLESHOOTING OF DTC P1401 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.
15
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.