P2635
Fuel Pump A Low Flow / Performance
The ECU detects insufficient fuel flow from fuel pump A. Either the pump is worn out, the supply line is restricted, or the pressure regulator does not allow proper flow.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
Common causes
Ordered by how often each turns out to be the cause.
- Worn fuel pumpCommon
- Clogged fuel filterPossible
- Pressure regulator faultLess likely
Parts involved
- Fuel Pump
- Fuel Filter
- Fuel Pressure Regulator
P2635 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.