DTC P0251 [MZ-CD 1.6 (Y6) (EURO4 emission level)]

id0102g6830500

DTC P0251

Fuel metering valve control circuit open
DETECTION CONDITION
•  The PCM monitors the load on the fuel metering valve control circuit.If the load does not change for a continuous 0.22 s when the PCM duty-controls the fuel metering valve, the PCM determines that there is an open circuit in the fuel metering valve control circuit.
POSSIBLE CAUSE
•  Fuel metering valve connector or terminal malfunction
•  Open circuit in the wiring harness between main relay and fuel metering valve terminal B
•  Short to ground in wiring harness between ENG INJ fuse and fuel metering valve terminal B
•  PCM connector or terminal malfunction
•  Open circuit in the wiring harness between fuel metering valve terminal A and PCM terminal 212
•  Fuel metering valve malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has the 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 RELATED 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
INSPECT FUEL METERING VALVE CONNECTOR CONDITION
•  Switch the ignition to OFF.
•  Disconnect the fuel metering 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 8.
No
Go to the next step.
4
VERIFY WHETHER MALFUNCTION IS FUEL METERING VALVE POWER SUPPLY CIRCUIT OR ELSEWHERE
•  Fuel metering valve connector is disconnected.
•  Switch the ignition to ON.
•  Measure the voltage between fuel metering valve harness side connector terminal B and body ground.
•  Is the voltage B+?
Yes
Go to Step 6.
No
Go to the next step.
5
CLASSIFY OPEN CIRCUIT OR SHORT TO GROUND CIRCUIT
•  Verify the ENG INJ fuse condition.
•  Is the ENG INJ fuse normal?
Yes
Repair or replace for a possible open circuit between main relay and fuel metering valve terminal B, then go to Step 8.
No
If the fuse is blown:
•  Repair for a possible short to ground between ENG INJ fuse and fuel metering valve terminal B.
If the fuse is deterioration:
•  Replace the fuse.
Then go to Step 8.
6
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 8.
No
Go to the next step.
7
INSPECT FUEL METERING VALVE CONTROL CIRCUIT FOR OPEN CIRCUIT
•  Fuel metering valve and PCM connectors are disconnected.
•  Inspect for continuity between fuel metering valve terminal A (wiring harness-side) and PCM terminal 212 (wiring harness-side).
•  Is there continuity?
Yes
Replace the fuel metering valve, then go to the next step.
(Fuel metering valve internal circuit open)
(See SUPPLY PUMP REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)
No
Repair or replace the wiring harness for a possible open circuit, then go to the next step.
8
VERIFY THAT DTC P0251 TROUBLESHOOTING IS COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Run the vehicle under the FREEZE FRAME DATA stored condition.
•  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.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the after repair procedure.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZ-CD 1.6 (Y6) (EURO4 emission level)].)
No
DTC troubleshooting completed.