Powertrain, generic · Fuel and air metering, auxiliary emission controls

P00C6 Fuel Rail Pressure Too Low - Engine Cranking

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Direct-injection engines release injection only once the rail has reached a minimum pressure. P00C6 is set when this pressure is not reached quickly enough while cranking, or, in another documented variant, when it drops below the minimum again right after the high-pressure start. Cranking then takes longer or the engine does not start. The check runs once per start; some manufacturers only enable it above a minimum tank level.

Likely causes

High-pressure pump weak, or its drive cam or follower worn
Lift pump or low-pressure supply too weak
Control valve on the pump faulty
Leak or check valve fault letting pressure bleed off after shutdown
Very low fuel level

Symptoms

  • Check engine light on
  • Long cranking
  • No start
  • Jerking after starting

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–900
Time1–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

high pressure fuel pumplow pressure fuel pumpfuel pressure regulatorrail pressure sensor

Related codes

P0087P0088P0089P0090P053F

References: law.cornell.edu, newtonnet.co.uk, gsi.ext.gm.com.