DTC Code | DTC Name |
---|---|
P1271 | Fuel Regulator Circuit Malfunction (EDU Drive) |
P1272 | Fuel Pressure Regulator Malfunction |
DESCRIPTION
The ECM controls the internal fuel pressure of the common rail assembly by opening and closing the pressure discharge valve. When sudden deceleration occurs, the internal fuel pressure will temporarily become higher than usual and combustion noise may result. Therefore the ECM will open the valve temporarily to discharge the excess pressure inside the common rail assembly. Also, the pressure discharge valve opens when the ignition switch is turned off to allow prompt discharge of the common rail assembly internal pressure and so that the engine stops smoothly.
For more information on the pressure discharge valve and common rail system.
Click hereНажмите здесь
For more information on the injector driver (EDU).
Click hereНажмите здесь
If P1271 and/or P1272 is present, refer to the DTC chart for the fuel system.
Click hereНажмите здесь
*1 | Return to Fuel Tank (Low Pressure) |
*2 | From Common Rail Assembly (High Pressure) |
*3 | Solenoid |
*4 | Valve |
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
---|---|---|---|---|---|
P1271 | Fuel Regulator Circuit Malfunction (EDU Drive) |
When either condition below is met (1 trip detection logic):
|
|
Comes on | DTC stored |
P1272 | Fuel Pressure Regulator Malfunction |
Pressure discharge valve does not open. Actual pressure decreasing rate deviates from the simulated pressure decreasing rate after the ignition switch is turned off (2 trip detection logic). |
|
Comes on | DTC stored |
DTC No. | Data List |
---|---|
P1271 |
|
P1272 |
After confirming DTC P1271 and/or P1272, check the fuel pressure inside the common rail in "Powertrain / Engine and ECT / Data List / All Data / Fuel Press" using the GTS.
P1271:
After clearing the DTC, drive the vehicle at 50 km/h (31 mph) in third gear, and then decelerate by releasing the accelerator pedal. Check that P1271 is not present.
P1272:
After clearing the DTC, start and stop the engine twice (wait 30 seconds or more after turning the ignition switch off before starting the engine the second time), and then confirm that P1272 is not stored.
Engine Speed | Fuel Pressure (kPa) |
---|---|
Idling | Fuel Press is within +/-5000 kPa of Target Common Rail Pressure |
2500 rpm (No engine load) |
Condition | Fuel Press (Idling) | Fuel Press (1 Second after Engine Stopped) |
---|---|---|
Pressure discharge valve normal | 35000 kPa | 170 kPa |
Open in pressure discharge valve circuit | 34000 kPa | 34300 kPa |
MONITOR DESCRIPTION
This DTC will be set if there is no valve opening confirmation (IJf) signal sent from the injector driver (EDU) to the ECM, despite the ECM has commanded the injector driver (EDU) to open the pressure discharge valve. This DTC refers to an open or short circuit malfunction of the pressure discharge valve circuit, not a malfunction in which a valve is stuck open or closed.
The injector driver (EDU) monitors the current supplied to the pressure discharge valve to verify that the current flows into the valve. If the current exceeds the specified level, the injector driver (EDU) interprets this as the IJf signal being low. If this DTC is stored, the ECM enters the fail-safe mode and limits engine power. The fail-safe mode continues until the ignition switch is turned off.
The pressure discharge valve will open and discharge the internal fuel pressure from the common rail assembly to the fuel tank when the ignition switch is turned off. In this event, the ECM compares the actual drop rate of the internal fuel pressure and the target drop rate. If the ECM judges that the actual drop rate is smaller than the target, the ECM then judges that the valve is stuck closed and stores this DTC. This DTC will be stored if the internal fuel pressure does not drop to the target after the ignition switch has been turned off.
If this DTC is stored, the ECM enters fail-safe mode and limits engine power. The fail-safe mode continues until the ignition switch is turned off.
MONITOR STRATEGY
Required sensors | Injector driver (EDU) |
Frequency of operation | Continuous |
Duration | 3 seconds |
MIL operation | 1 driving cycle |
Required sensors | Fuel pressure sensor |
Frequency of operation | Once per driving cycle |
Duration | 1 second |
MIL operation | 2 driving cycles |
TYPICAL ENABLING CONDITIONS
Specification |
---|
The vehicle is driven at 50 km/h (31 mph) in 3rd gear, and then decelerated by complete release of the accelerator pedal 3 times. |
Item | Specification | |
---|---|---|
Minimum | Minimum | |
Fuel pressure |
30000 kPa (306 kgf/cm2, 4350 psi) |
- |
Fuel temperature | 0°C (32°F) | - |
Battery voltage | 11 V | - |
The monitor will not run if the fuel pressure sensor, pressure discharge valve circuit or fuel temperature sensor is malfunctioning. |
TYPICAL MALFUNCTION THRESHOLDS
Specification |
---|
There are no confirmation signals from the injector driver (EDU) for a specific number of times consecutively, despite the ECM sending command signals regularly during deceleration. |
Specification |
---|
The internal pressure stays beyond the specified level after the ignition switch is turned off. |
CONFIRMATION DRIVING PATTERN
DTC No. | DTC Detection Drive Pattern |
---|---|
P1271 | Ignition switch ON to off and drive the vehicle at 50 km/h (31 mph) in 3rd gear, and then decelerate by releasing the accelerator pedal |
P1272 | Ignition switch ON to off |
WIRING DIAGRAM
*a | Pressure Discharge Valve (Built into Common Rail Assembly) |
*b | Injector Driver (EDU) |
Refer to DTC P0201 for injector driver (EDU) power source circuit.
Click hereНажмите здесь
CAUTION / NOTICE / HINT
After replacing the ECM, the new ECM needs registration (Click here) and initialization (Click hereНажмите здесь).
After completing repairs, confirm that P1271 and/or P1272 does not recur.
If P062D and P1271 are present simultaneously, there is an open in the INJF wire harness between the injector driver (EDU) and ECM, or there is an open in the wire harness for both an injector and the pressure discharge valve.
Read freeze frame data using the GTS. 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 WHETHER DTC OUTPUT RECURS
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCsTurn the ignition switch off for 30 seconds or more.
Start the engine and turn the GTS on.
Drive the vehicle at 50 km/h (31 mph) in 3rd gear, and then decelerate by completely releasing the accelerator pedal. Perform this 3 times.
ОСТОРОЖНО
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the pending DTCs.
Powertrain > Engine and ECT > Trouble CodesResult | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
B | Нажмите здесь |
C |
GO TO DTC CHART Click here Нажмите здесь |
A |
CHECK PRESSURE DISCHARGE VALVE (OPERATION)
Check the pressure discharge valve operation.
Click here Нажмите здесь
Result | |||
---|---|---|---|
|
OK | Нажмите здесь |
GO TO STEP 14 |
NG | Нажмите здесь |
GO TO STEP 12 |
INSPECT COMMON RAIL ASSEMBLY (PRESSURE DISCHARGE VALVE)
Inspect the common rail assembly.
Click hereНажмите здесь
Result | |||
---|---|---|---|
|
NG | Нажмите здесь |
OK |
CHECK HARNESS AND CONNECTOR (PRESSURE DISCHARGE VALVE - INJECTOR DRIVER (EDU))
Disconnect the pressure discharge valve connector.
Disconnect the injector driver (EDU) connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG | Нажмите здесь |
OK |
CHECK HARNESS AND CONNECTOR (INJECTOR DRIVER (EDU) - ECM)
Disconnect the injector driver (EDU) connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG | Нажмите здесь |
GO TO STEP 11 |
OK |
CHECK TERMINAL VOLTAGE (POWER SOURCE OF INJECTOR DRIVER (EDU))
Click hereНажмите здесь
Result | |||
---|---|---|---|
|
NG | Нажмите здесь |
OK |
REPLACE INJECTOR DRIVER (EDU)
Replace the injector driver (EDU).
Click hereНажмите здесь
Result | ||
---|---|---|
|
NEXT |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCsTurn the ignition switch off for 30 seconds or more.
Start the engine and turn the GTS on.
Drive the vehicle at 50 km/h (31 mph) in 3rd gear, and then decelerate by completely releasing the accelerator pedal. Perform this 3 times.
ОСТОРОЖНО
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the pending DTCs.
Powertrain > Engine and ECT > Trouble CodesIf no pending DTCs are output, proceed to the next step to check "All Readiness".
Perform the following procedure using the GTS to determine whether or not the DTC judgment has been carried out.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Powertrain > Engine and ECT > UtilityTester Display |
---|
All Readiness |
Input DTC P1271 and P1272.
Check the DTC judgment result.
Result | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
|
If STATUS is INCOMPLETE or N/A, perform the following procedure 3 times: drive the vehicle at 50 km/h (31 mph) in 3rd gear, and then decelerate by completely releasing the accelerator pedal.
A |
END |
B |
REPLACE ECM
Replace the ECM.
Click hereНажмите здесь
Result | ||
---|---|---|
|
NEXT | Нажмите здесь |
GO TO STEP 14 |
GO TO INJECTOR CIRCUIT
Go to injector circuit.
Click hereНажмите здесь
Result | ||
---|---|---|
|
NEXT | Нажмите здесь |
GO TO STEP 14 |
REPAIR OR REPLACE HARNESS OR CONNECTOR
Repair or replace the harness or connector.
Result | ||
---|---|---|
|
NEXT | Нажмите здесь |
GO TO STEP 14 |
REPLACE COMMON RAIL ASSEMBLY
Replace the common rail assembly.
Click hereНажмите здесь
Result | ||
---|---|---|
|
NEXT |
BLEED AIR FROM FUEL SYSTEM
Bleed the air from the fuel system.
Click hereНажмите здесь
Result | ||
---|---|---|
|
NEXT |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCsTurn the ignition switch off for 30 seconds or more.
Start the engine and turn the GTS on.
Drive the vehicle at 50 km/h (31 mph) in 3rd gear, and then decelerate by completely releasing the accelerator pedal. Perform this 3 times.
ОСТОРОЖНО
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Confirm that the pending DTC is not output.
Powertrain > Engine and ECT > Trouble CodesPerform the following procedure using the GTS to determine whether or not the DTC judgment has been carried out.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Powertrain > Engine and ECT > UtilityTester Display |
---|
All Readiness |
Input DTC P1271 and P1272.
Check the DTC judgment result.
If STATUS is INCOMPLETE or N/A, perform the following procedure 3 times: drive the vehicle at 50 km/h (31 mph) in 3rd gear, and then decelerate by completely releasing the accelerator pedal.
Result | ||
---|---|---|
|
NEXT |
END |