| DTC Code | DTC Name |
|---|---|
| P1229 | Fuel Pump System |
DESCRIPTION
Refer to the SYSTEM DESCRIPTION Click here.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P1229 | Fuel over-feed: Fuel pressure is beyond the target fuel pressure despite ECM closing suction control valve (1 trip detection logic) |
|
Tech Tips
For more information on the supply pump (suction control valve) and common rail system, refer to the system description Click here.
When DTC P1229 is stored, check the internal fuel pressure of the common rail by entering the following menus on the intelligent tester: Powertrain / Engine and ECT / Data List / Fuel Press.
| Reference | ||||||
|---|---|---|---|---|---|---|
|
MONITOR DESCRIPTION
P1229 (Fuel over-feed):The ECM sets this DTC if the actual fuel pressure inside the common rail remains higher than the target fuel pressure, despite the ECM closing the suction control valve. This DTC indicates that the suction control valve may be stuck open, or that there may be a short circuit. Under this condition, the pressure discharge valve operates frequently.
If this DTC is set, the ECM enters fail-safe mode and limits the engine power. The fail-safe mode continues until the ignition switch is turned OFF.
MONITOR STRATEGY
| Required sensor | Fuel pressure sensor |
| Frequency of operation | Continuous |
| Duration | 1 minute |
| MIL operation | 1 driving cycle |
TYPICAL ENABLING CONDITIONS
| Item | Specification |
|---|---|
| Target fuel pressure variation | Small |
| The monitor will not run if the fuel pressure sensor, suction control valve circuit, or pressure discharge valve is malfunctioning. | |
TYPICAL MALFUNCTION THRESHOLDS
| Detection Criteria | Threshold |
|---|---|
| The fuel pressure of the common rail with the suction control valve closed. | Remains higher than targeted fuel pressure |
| Behavior of the pressure discharge valve | Frequently operates |
WIRING DIAGRAM
INSPECTION PROCEDURE
Tech Tips
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
PROCEDURE
CHECK OTHER DTC OUTPUT
Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Enter the following menus: Powertrain / Engine and ECT / DTC.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
GO TO DTC CHART Click here |
| A |
|
INSPECT SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE)
Disconnect the S8 suction control valve connector.
Measure the resistance of the suction control valve.
| Standard resistance | ||||||
|---|---|---|---|---|---|---|
|
| NG |
|
REPLACE SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE) Click here |
| OK |
|
CHECK IF DTC OUTPUT RECURS (DTC P1229)
Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Enter the following menus: Powertrain / Engine and ECT / DTC / Clear.
Clear the DTCs.
Disconnect the suction control valve connector and then start the engine. Wait for 1 minute.
Tech Tips
If the engine does not start, the suction control valve is normal. Therefore proceed to procedure 4.
Enter the following menus: Powertrain / Engine and ECT / DTC.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE) Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (SUCTION CONTROL VALVE - ECM (PROCEDURE 4))
Disconnect the S8 suction control valve connector.
Disconnect the E8 ECM connector.
Measure the resistance of the wire harness side connector.
| Standard resistance (Check for open) | |||||
|---|---|---|---|---|---|
|
| Standard resistance (Check for short) | |||||
|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT ECM (PCV VOLTAGE)
Inspect using the oscilloscope.
During cranking or idling, check the waveform between the specified terminals of the E8 ECM connector.
| Standard | ||||
|---|---|---|---|---|
|
| NG |
|
REPLACE ECM Click here |
| OK |
|
CHECK IF DTCS OUTPUT RECUR
Tech Tips
After clearing the DTC(s), drive the vehicle at 50 km/h (31 mph) for 5 minutes, and then confirm that DTC P1229 is not present again.
| NEXT |
|
END