DTC P0408:00 [SKYACTIV-D 1.5]

id0102q2895700

DTC P0408:00

LP-EGR control valve position sensor circuit high input
DETECTION CONDITION
•  If the PCM detects the LP-EGR control valve position sensor voltage at the PCM terminal 1AQ is 4.84 V or more for 2 s with the following condition met, the PCM determines that the LP-EGR control valve position sensor circuit voltage is high.
MONITORING CONDITIONS
―  Battery voltage: 8 V or more
―  0.5 s have elapsed after the ignition was switched ON (engine off or on)
Diagnostic support note
•  This is a continuous monitor (CCM).
•  The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA/Snapshot data is available.
•  DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION
•  PCM restricts engine torque.
•  Inhibits the EGR control.
POSSIBLE CAUSE
•  LP-EGR control valve connector or terminals malfunction
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between.
•  LP-EGR control valve position sensor power supply circuit and signal circuit are shorted to each other
•  Open circuit in wiring harness between the following terminals:
―  LP-EGR control valve terminal B—PCM terminal 1AQ
―  LP-EGR control valve terminal A—PCM terminal 1AR
•  LP-EGR control valve position sensor malfunction
•  PCM malfunction

Diagnostic Procedure

STEP

INSPECTION

ACTION
1
RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
Note
•  Recording can be facilitated using the screen capture function of the PC.
•  Record the FREEZE FRAME DATA/snapshot data on the repair order.
—
Go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT LP-EGR CONTROL VALVE CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the LP-EGR control valve connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 9.
No
Go to the next step.
4
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 9.
No
Go to the next step.
5
INSPECT LP-EGR CONTROL VALVE POSITION SENSOR CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the LP-EGR control valve and PCM connectors are disconnected.
•  Switch the ignition ON (engine off).
•  Measure the voltage at the following terminals (wiring harness-side).
―  LP-EGR control valve terminal C
―  LP-EGR control valve terminal B
―  LP-EGR control valve terminal A
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals.
•  LP-EGR control valve terminal C—PCM terminal 1AP
•  LP-EGR control valve terminal B—PCM terminal 1AQ
•  LP-EGR control valve terminal A—PCM terminal 1AR
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 9.
6
INSPECT LP-EGR CONTROL VALVE POSITION SENSOR POWER SUPPLY CIRCUIT AND SIGNAL CIRCUIT FOR SHORT TO EACH OTHER
•  Verify that the LP-EGR control valve and PCM connectors are disconnected.
•  Switch the ignition off.
•  Inspect for continuity between LP-EGR control valve terminals C and B (wiring harness-side).
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  LP-EGR control valve terminal C—PCM terminal 1AP
•  LP-EGR control valve terminal B—PCM terminal 1AQ
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to each other.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to each other.
Go to Step 9.
No
Go to the next step.
7
INSPECT LP-EGR CONTROL VALVE POSITION SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Verify that the LP-EGR control valve and PCM connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  LP-EGR control valve terminal B—PCM terminal 1AQ
―  LP-EGR control valve terminal A—PCM terminal 1AR
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  LP-EGR control valve terminal B—PCM terminal 1AQ
•  LP-EGR control valve terminal A—PCM terminal 1AR
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 9.
8
INSPECT LP-EGR CONTROL VALVE POSITION SENSOR
•  Reconnect all disconnected connectors.
•  Inspect the LP-EGR control valve position sensor.
•  Is there any malfunction?
Yes
Replace the LP-EGR control valve, then go to the next step.
(See LP-EGR CONTROL VALVE REMOVAL/INSTALLATION [SKYACTIV-D 1.5].)
No
Go to the next step.
9
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOEO or KOER self test.
•  Is the same DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-D 1.5].)
No
DTC troubleshooting completed.