ECD SYSTEM (w/o EGR Cooler Bypass Valve), Diagnostic DTC:P0088, P1229

DTC Code	DTC Name
P0088	Fuel Rail / System Pressure - Too High
P1229	Fuel Pump System

DESCRIPTION

Tech Tips

For more information on the supply pump (suction control valve) and common rail system, refer to the system description Click here.
If P0088 and/or P1229 is present, refer to the "Diagnostic Trouble Code (DTC) Table for Common Rail System" Click here.

DTC No.	DTC Detection Condition	Trouble Area
P0088	Internal fuel pressure of common rail is too high: Fuel pressure exceeds 200 MPa (2,039 kgf/ cm², 29,007 psi) (1 trip detection logic)	Suction control valve Pressure discharge valve Short in suction control valve circuit ECM
P1229	Fuel over-feed: Internal fuel pressure continues exceeding target fuel pressure despite ECM closing suction control valve (1 trip detection logic)	Short in suction control valve circuit Suction control valve ECM

DTC No.

DTC Detection Condition

Trouble Area

P0088

Internal fuel pressure of common rail is too high:

Fuel pressure exceeds 200 MPa (2,039 kgf/ cm², 29,007 psi)

(1 trip detection logic)

Suction control valve
Pressure discharge valve
Short in suction control valve circuit
ECM

P1229

Fuel over-feed:

Internal fuel pressure continues exceeding target fuel pressure despite ECM closing suction control valve

(1 trip detection logic)

Short in suction control valve circuit
Suction control valve
ECM

Tech Tips

When DTC P0088 and/or P1229 is set, 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.

Standard

Engine Speed	Fuel Pressure
Idling	Approximately 30 to 40 MPa
3,000 rpm (No engine load)	Approximately 85 to 105 MPa

MONITOR DESCRIPTION

P0088 (Internal fuel pressure too high):

The ECM sets this DTC if the fuel pressure inside the common rail is beyond 200 MPa (2,039 kgf/cm², 29,007 psi). This DTC indicates that: 1) the suction control valve may be stuck open, 2) there may be an open or short in the suction control valve circuit.

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.

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 there may be a short in its 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.

WIRING DIAGRAM

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, and other data from the time the malfunction occurred.

Note

If the ECM is replaced, the new ECM needs initialization Click here.

PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0088 AND/OR P1229)

Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / DTC.

Read the DTCs.

Result

Display (DTC Output)	Proceed to
P0088, or P0088 and P1229	A
P1229	B
P0190, P0191, P0192, P0193 and/or P1271	C
P1272	D

INSPECT SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE) Click here

GO TO DTC CHART

REPLACE COMMON RAIL ASSEMBLY (PRESSURE DISCHARGE VALVE) Click here

READ VALUE USING INTELLIGENT TESTER (SEE IF DTC P1272 IS OUTPUT)

Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / DTC / Clear.
Clear the DTC Click here.
Start the engine and turn the ignition switch OFF. Wait for 10 seconds and then restart the engine and turn the ignition switch OFF again.
Select the following menu items: Powertrain / Engine and ECT / DTC.

Read the DTCs.

Result

Display (DTC Output)	Proceed to
P1272	A
No output	B

INSPECT SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE) Click here

REPLACE COMMON RAIL ASSEMBLY (PRESSURE DISCHARGE VALVE)

NEXT
CHECK WHETHER DTC OUTPUT RECURS (DTC P0088 AND/OR P1229)

Tech Tips

After clearing the DTC(s), drive the vehicle at 50 km/h (31 mph) for 5 minutes, and then confirm that P0088 and/or P1229 is not present again.

NEXT

END

INSPECT SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE)

Text in Illustration

*1 Suction Control Valve

Disconnect the S11 suction control valve connector.

Text in Illustration
*1	Suction Control Valve

Measure the resistance of the suction control valve.

Standard resistance

Tester Connection	Condition	Specified Condition
1 - 2	20°C (68°F)	1.9 to 2.3 Ω

Reconnect the suction control valve connector.

REPLACE SUCTION CONTROL VALVE

CHECK WHETHER DTC OUTPUT RECURS (DTC P1229)

Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Clear DTCs Click here.
Disconnect the suction control valve connector and then start the engine. Wait for 1 minute.
Select the following menu items: Powertrain / Engine and ECT / DTC.

Read the DTCs.

Result

Display (DTC Output)	Proceed to
No output or engine does not start	A
P1229	B

Reconnect the suction control valve connector.

REPLACE SUCTION CONTROL VALVE

CHECK HARNESS AND CONNECTOR (SUCTION CONTROL VALVE - ECM)

Text in Illustration
*1	Suction Control Valve Connector
*2	ECM Connector
*a	Wire Harness Side
*b	Front View

Disconnect the S11 valve connector.

Disconnect the E6 ECM connector.

Check the resistance.

Standard resistance (Check for open)

Tester Connection	Specified Condition
S11-1 (Suction control valve) - E6-2 (PCV+)	Below 1 Ω
S11-2 (Suction control valve) - E6-1 (PCV-)	Below 1 Ω

Standard resistance (Check for short)

Tester Connection	Specified Condition
S11-1 (Suction control valve) or E6-2 (PCV+) - Body ground	10 kΩ or higher
S11-2 (Suction control valve) or E6-1 (PCV-) - Body ground	10 kΩ or higher

Reconnect the ECM connector.
Reconnect the suction control valve connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT ECM (PCV SIGNAL)

Text in Illustration
*1	ECM Connector

While cranking or idling the engine, check the waveform of the ECM connector using an oscilloscope.

OK
Correct waveform is shown

ECM Terminal Name	PCV+ (E6-2) - PCV- (E6-1)
Tester Range	10 V/DIV., 5 msec./DIV.
Condition	Idling or cranking with warm engine

Tech Tips

The waveform varies depending on the suction control valve operation.
After clearing the DTC(s), drive the vehicle at 50 km/h (31 mph) for 5 minutes, and then confirm that P0088 or P1229 is not output again.

REPLACE ECM

CHECK WHETHER DTC OUTPUT RECURS (DTC P0088 AND/OR P1229)