5.
Read "DTC Status" parameter.
The PCM provides ground to one side of the coil in the fuel pump relay to control the fuel pump relay. The other side of the fuel pump relay coil is connected to fuel pump relay, which activates when the ignition switch is ON. The PCM monitors the control circuit between the fuel pump relay and the ECM. When the ignition switch is turned ON, the PCM energizes the fuel pump relay, which sends power to the fuel pump.
If there is Short to ground in fuel pump circuit, PCM sets DTC P0231.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Circuit continuity check, low | ● Poor connection ● Short to ground in control circuit ● Fuel pump relay |
Enable Conditions | ||
Threshold Value | ||
Diagnostic Time | ● Short circuit to Ground | |
MIL ON Condition | ● DTC only |
Temperature [℃ (℉)] | Coil Resistance (Ω) |
20 (68) | 70.0 ~ 120.0 |
Connect scantool to Data Link Connector(DLC).
IG "ON".
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC'sinformation from the DTCs menu
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditionsnoted in the freeze frame data or enable conditions noted in the DTC detecting condition.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
History fault : DTC occurred but has been cleared.
Present fault : DTC is occurring at present time.
▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or wasrepaired and ECM memory was not cleared. Thoroughly check connectors for looseness,poor connection, bending, corrosion, contamination, deterioration, or damage.Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
▶ Go to "Terminal & Connector Inspection" procedure
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure.
▶ Go to "Fuel pump relay circuit inspection" procedure.
Key "OFF".
Disconnect fuel pump relay.
Key "ON".
Measure the voltage between terminal 5 of fuel pump relay harness connector and chassis ground.
Specification : Approx. 3.5V
Is the measured voltage within specifications?
▶ Go to "Component inspection" procedure.
▶ Repair short to ground in control circuit, and go to "Verification of vehicle Repair" procedure.
Fuel pump relay check.
Key "OFF".
Disconnect fuel pump relay.
Measure the resistance between terminal 1 and 2 of fuel pump relay component side.
Measure the resistance between terminal 3 and 5 of fuel pump relay component side.
Terminal | Power Approval |
1~2 | NO |
3~5 | YES (70Ω ~ 120Ω) |
Is the measured resistance within specification?
▶ Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage. So, check poor connections and the related circuit between ECM and component thoroughly. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good Fuel pump relay and check for proper operation.
▶ If the problem is corrected, replace Fuel pump relay and go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete".
If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC.
▶ Go to the applicable troubleshooting procedure.
