P2A8E code meaning
Alternative Fuel Pump A Performance
Powertrain system Generic code P2Axx codes Check engine light
What P2A8E means
P2A8E reports that alternative fuel pump A no longer delivers what it should, a mechanical or hydraulic fault rather than an electrical one. Such pumps move liquid fuel, typically LNG out of a cryogenic tank. A patent application now held by Cespira, US20080302111A1, shows how a controller can judge them from the delivery line pressure alone: each time the pump is commanded on, pressure has to climb from a lower to an upper set point within a known range of slopes. A clearly flatter rise means lost volumetric efficiency, and a falling pressure means the pump cannot even keep up with the engine. The document names worn piston seals, leaking static seals or check valves, dirt in the fuel and a weak hydraulic drive as causes. No manufacturer publishes P2A8E or its limits.
P2A8E at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor3 to 10 hours
- Clears after repairAfter a drive cycle
Symptoms of P2A8E
- Malfunction lamp on
- Power loss at high load, gas pressure sagging
- Pump runs noticeably longer to refill the accumulator
- Engine switched to reduced output or diesel-only operation
Common causes of P2A8E
- Most likelyWorn dynamic piston seals in pump A
- PossibleLeaking inlet or outlet check valve of pump A
- PossibleHydraulic drive of pump A delivering too little force or speed
- Less likelyImpurities in the fuel passing the filter and damaging the pump
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Alt fuel pump aAlt fuel filter
What each part of P2A8E means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| 8E | The exact fault in that area. |
What to do next
- Note P2A8E and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2A8E
What does P2A8E mean?
P2A8E means "Alternative Fuel Pump A Performance". P2A8E reports that alternative fuel pump A no longer delivers what it should, a mechanical or hydraulic fault rather than an electrical one. It is a generic code, so it means the same on every make.
Is it safe to drive with P2A8E?
Drive gently and only to a workshop. With P2A8E the car can go into limp mode (reduced power) to protect itself.
Will P2A8E fail an emissions test?
Yes, it can. P2A8E is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2A8E to fix?
Difficulty: workshop only. A typical repair takes 3 to 10 hours of work. This is a job for a workshop.
Will P2A8E clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.