DTC P1400[AJ (3.0L Duratec)]
id0102a4824900
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DTC P1400 |
Differential Pressure Feedback (D.P.F.) EGR sensor circuit low voltage detected |
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DETECTION CONDITION
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• 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.
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POSSIBLE CAUSE
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• Short to ground in wiring between D.P.F. EGR sensor terminal C and PCM terminal 65
• Damaged D.P.F. EGR sensor
• Short to ground in wiring between D.P.F. EGR sensor terminal A and PCM terminal 90
• Damaged PCM
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Diagnostic procedure
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STEP |
INSPECTION |
ACTION |
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1
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VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
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Yes
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Go to next step.
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No
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Record the FREEZE FRAME DATA on the repair order, then go to next step.
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2
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VERIFY SERVICE INFORMATION AVAILABILITY
• Verify related Service Information availability.
• Is any related Service Information available?
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Yes
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Perform repair or diagnosis according to the available Service Information.
• If the vehicle is not repaired, go to next step.
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No
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Go to next step.
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3
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INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA
• Is DTC P1400 on FREEZE FRAME DATA?
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Yes
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Go to next step.
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No
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Go to FREEZE FRAME DATA DTC inspection.
(See DTC TABLE[AJ (3.0L Duratec)].)
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4
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DETERMINE PRESENT DPFEGR PID VOLTAGE
• Turn the ignition switch to the ON position.
• Access DPFEGR PID.
• Is DPFEGR PID voltage less than 0.2 V?
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Yes
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Go to the next step.
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No
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Go to Step 8.
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5
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ATTEMPT TO INDUCE OPPOSITE D.P.F. EGR SENSOR VOLTAGE
• Disconnect D.P.F. EGR sensor.
• Turn the ignition switch to the ON position.
• Is DPFEGR PID value 4.0—6.0 V?
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Yes
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Replace D.P.F. EGR sensor, then go to Step 9.
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No
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Go to the next step.
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6
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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?
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Yes
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Go to the next step.
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No
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Go to symptom troubleshooting “No.27 CONSTANT VOLTAGE” diagnostic procedure.
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7
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CHECK D.P.F. EGR CIRCUIT FOR SHORT TO GROUND AND SIG RTN IN HARNESS
• Disconnect M-MDS 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?
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Yes
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Replace PCM, then go to Step 9.
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No
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Repair short to ground or SIG RTN circuit, then go to Step 9.
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8
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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?
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Yes
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Repair or replace malfunctioning part, then go to the next step.
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No
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Unable to duplication or identify fault at this time.
Go to the next step.
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9
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VERIFY TROUBLESHOOTING OF DTC P1400 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the M-MDS.
• Perform KOEO/KOER self test.
• Is the PENDING CODE same DTC present?
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Yes
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Replace PCM, then go to next step.
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No
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Go to the next step.
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10
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VERIFY AFTER REPAIR PROCEDURE
• Perform "AFTER REPAIR PROCEDURE".
• Is there any DTC present?
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Yes
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Go to applicable DTC inspection.
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No
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Troubleshooting completed.
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