DTC Advanced Diagnostics: P0088
DTC P0088:Fuel Rail Pressure Too High

General Description

The powertrain control module (PCM) controls fuel pressure delivered by the high pressure fuel pump. If the actual fuel pressure deviates from the target fuel pressure for a set time, the PCM detects a malfunction. The DTC is also stored when the pressure relief valve is opened to protect the fuel hose when the fuel reaches an abnormally high pressure.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Once per driving cycle
Sequence
None
Duration
4.0 seconds or more
DTC Type
One drive cycle, MIL on

Enable Conditions
Condition
Minimum
Maximum
Elapsed time after returning from fuel cut
3.0 seconds
–
State of the engine
Running
Other
Other than initial engine start

Malfunction Threshold
Either of these condition is met:
The actual fuel pressure is 7,750 kPa (79.03 kgf/cm2, 1,124.1 psi) or more for at least 4.0 seconds when target fuel pressure is 2,500 kPa (25.49 kgf/cm2, 362.6 psi).
The actual fuel pressure is 20,250 kPa (206.5 kgf/cm2, 2,937.1 psi) or more for at least 4.0 seconds when target fuel pressure is 15,000 kPa (152.96 kgf/cm2, 2,175.6 psi).
The actual fuel pressure is 23,000 kPa (234.5 kgf/cm2, 3,335.9 psi) or more.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes
High pressure fuel pump failure
Fuel rail pressure sensor range/performance problem

Confirmation Procedure
Operating Condition
1.
Start the engine.
2.
Drive the vehicle repeated acceleration and deceleration.
When freeze data is stored, drive the vehicle under those conditions instead of Driving Pattern step 2.
Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
Select the DI Fuel Pressure Test in the INSPECTION MENU with the HDS.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.