OBD-II code · Powertrain (generic, extended)

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.

Is it safe to drive with P2635?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyWorn fuel pump
  • PossibleClogged fuel filter
  • Less likelyPressure regulator fault

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

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–2.5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Fuel Pump, Fuel Filter, Fuel Pressure Regulator

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.