PACCAR MX P0088 is the fault code chapter the 2013 PACCAR MX Diagnostic Service Manual publishes for “Fuel Pressure – Data valid but too high”. The 3-page PDF is PACCAR’s own troubleshooting write-up for EPA2013 MX engines, reproduced exactly as the factory issued it.
Document details and coverage
| Brand | PACCAR |
|---|---|
| Group | DTCs / MX Engines (EPA2013) |
| Fault code | P0088 |
| Fault code information | 1 trip MIL, 3 drive cycle recovery, freeze frame type Fuel |
| Source manual | 2013 PACCAR MX Diagnostic Service Manual |
| Pages | 3 |
| File size | 0.4 MB |
| Format | |
| Language | English |
What sets PACCAR MX P0088 active
The diagnostic runs when the engine has been running for more than 200 seconds. The PCI ECU (D420) sets the code when the fuel pressure is 14 bar [203 psi] or more for more than 10 seconds. The DTC goes inactive when the fault is no longer detected; the repair is validated by keying the ignition off for at least 15 seconds, keying on, then running the engine at several speeds across the range for more than 10 seconds.
Component and wiring checks
- PCI ECU connector D420.A pins A38 (ground), A46 (power supply) and A50 (fuel pressure signal) to sensor connector F801 pins 4, 2 and 1
- Five volts between wiring harness pins 2 and 4 with the ignition keyed on
- Comparison of the measured pressure against the reading shown in DAVIE
Possible causes and repair notes
- Restriction in the fuel to tank return circuit
- Faulty fuel pressure regulating valve
- Faulty fuel pressure sensor (F801), or a PCI failure if the DAVIE reading does not change
The low-pressure fuel pressure is measured by the fuel pressure sensor (F801) at the end of the low-pressure fuel supply gallery, and the manual has the technician check the fuel pressure according to the prescribed job before condemning parts. The verification drive cycle is run with DAVIE connected, errors cleared, and the engine idling. Company and product background is on the official PACCAR website.
Who needs this PACCAR MX P0088 chapter
Heavy-duty diesel technicians and fleet shops reach for PACCAR MX P0088 when the code lands on a DAVIE scan and the repair has to follow the factory sequence instead of guesswork.
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