Engine Fuel Rail Pressure Very High
The VOLVO-MACK-MID128-PID1569-FMI0 (Volvo/Mack D/MP Series) diesel fault code means: Engine Fuel Rail Pressure Very High. This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $600-$3,500
Down with a Volvo fault on the road?
Get connected with a verified mobile diesel mechanic near you. Verified diesel & reefer techs, launching on the freight corridor.
Find a mobile mechanic →A $30 car code reader can't do diesel. The HD7000 reads full-system codes and does parked DPF regen, idle/speed-limit, and service resets from the cab — on everything from a 6.7 Cummins/Power Stroke/Duramax pickup to Class-8 trucks (Detroit, Paccar, CAT, Volvo, Mack, International).
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Full-system 6/9/16-pin diesel scan tool for Cummins, Paccar, CAT, Detroit and more — plug-and-play, no subscription. A cheaper way to read heavy-duty codes a basic OBD2 scanner skips entirely.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Common Symptoms
- Hard start, long cranking, or no-start
- Power loss, rough idle, surging
- Engine derate warning on dash
- Check Engine Light illuminated
- Increased fuel consumption
- Smoke (black or white) under load
Probable Causes (Ranked by Likelihood)
- Failed high-pressure fuel pump (aged CP-series pump) Likely
- Leaking or stuck injector returning excessive fuel Likely
- Clogged fuel filters or restricted supply line Possible
- Failed fuel rail pressure sensor Possible
- Stuck fuel pressure relief valve Less Likely
Step-by-Step Diagnostic Procedure
Connect Volvo PTT or Mack Guided Diagnostics and observe commanded vs actual rail pressure at idle, cranking, and under load.
Replace primary and secondary fuel filters; check water separator for contamination.
Run the dealer fuel return flow / leakback test and record milliliters per injector — a high-return cylinder indicates a leaking injector.
Measure supply pressure to the high-pressure pump with a mechanical gauge (spec per service manual, typically 5-10 psi).
If supply, filters, and injectors test good, replace the high-pressure pump assembly and clean the entire fuel rail system.
After pump or injector replacement, follow the Volvo/Mack fuel system prime procedure before starting.
Frequently Asked Questions
What does Volvo/Mack code MID128-PID1569-FMI0 mean?
Volvo/Mack code MID128-PID1569-FMI0 (Engine Fuel Rail Pressure Very High) is a serious-severity diagnostic trouble code set on D11/MP7, D13/MP8, and D16/MP10 diesel engines in Volvo VNL/VNR and Mack Anthem/Pinnacle/Granite/Titan trucks. It indicates a fault in the fuel rail system and should be read with Volvo Premium Tech Tool (PTT) or Mack Guided Diagnostics.
Can I drive a Volvo or Mack truck with code MID128-PID1569-FMI0?
Short distances may be acceptable to reach a repair facility, but the fault will escalate to derate (typically 55 mph then 5 mph on aftertreatment faults). Do not defer diagnosis beyond a shift.
How much does it cost to fix Volvo/Mack code MID128-PID1569-FMI0?
Typical repair falls in the range $600-$3,500. Sensor/wiring repairs are at the low end; EGR cooler, NOx sensor set, DEF pump, injector, or head work runs at the high end. Volvo PTT or Mack Guided Diagnostics is normally required for calibration and parameter programming.