DTC P0231 [AJ (3.0L Duratec)]

id0102a4819800

DTC P0231

FP secondary circuit low

DETECTION CONDITION

• If input voltage at PCM terminal 40 is remains low, PCM determines that FP secondary circuit has a malfunction.

POSSIBLE CAUSE

• Fuel pump relay malfunction
• Connector or terminal malfunction
• Short to ground in wiring between fuel pump relay terminal 87 and PCM terminal 40
• Open circuit in wiring between main relay and fuel pump relay terminal 30
• Open circuit in wiring between fuel pump relay terminal 87 and PCM terminal 40
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
Yes
Go to next step.
No
Record FREEZE FRAME DATA on repair order, then go to next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If vehicle is not repaired, go to next step.
No
Go to next step.
3
INSPECT FUEL PUMP RELAY CONNECTOR FOR POOR CONNECTION
• Turn ignition key to OFF.
• Disconnect the fuel pump relay.
• Check for poor connection (damaged/pulled-out pins, corrosion, etc.).
• Is there malfunction?
Yes
Repair or replace terminal, then go to Step 8.
No
Go to next step.
4
INSPECT PCM CONNECTOR FOR POOR CONNECTION
• Turn ignition key to OFF.
• Disconnect PCM connector.
• Check for poor connection (damaged/pulled-out pins, corrosion, etc.).
• Is there malfunction?
Yes
Repair or replace terminal, then go to Step 8.
No
Go to next step.
5
INSPECT FUEL PUMP RELAY POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT
• Turn ignition key to ON (Engine OFF).
• Measure voltage between fuel pump relay connector terminal 30 (harness-side) and body GND.
• Is voltage B+?
Yes
Go to next step.
No
Repair or replace wiring harness for open, then go to Step 8.
6
INSPECT FUEL PUMP CONTROL CIRCUIT FOR SHORT TO GND
• Turn ignition key to ON (Engine OFF).
• Inspect for continuity between fuel pump relay connector terminal 87 (harness-side) and body GND.
• Is there continuity?
Yes
Repair or replace the wiring harness for a short to GND, then go to Step 8.
No
Go to next step.
7
INSPECT FUEL PUMP RELAY
• Inspect the fuel pump relay.
• Is there any malfunction?
Yes
Replace the fuel pump relay, then go to next step.
No
Go to next step.
8
VERIFY TROUBLESHOOTING OF DTC P0231 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear DTC from memory using WDS or equivalent.
• Start engine.
• Perform "KOEO/KOER self-test"
• Is same DTC present?
Yes
Replace PCM, then go to next step.
No
Go to next step.
9
VERIFY AFTER SERVICE PRECAUTION
• Perform "AFTER SERVICE PRECAUTION".
• Is there any DTC present?
Yes
Go to applicable DTC inspection.
No
Troubleshooting completed.