Powertrain, generic (extended)

P2291 Injector Control Pressure Too Low - Engine Cranking

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2291 judges pressure build-up while the starter is turning. On HEUI diesels the injectors only fire once injector control pressure has reached a minimum, so any leak in the pressurised oil circuit shows up as a long crank or a no-start; Wikipedia's Power Stroke article names a contaminated injection pressure regulator and failed high-pressure oil seals as typical no-start causes on the 6.0 L. Ford also reuses the code on its current common-rail diesels: the 2023 summary for the 3.0 L and 6.7 L sets P2291 when rail pressure stays under 14,000 kPa for 20 s of cranking. Ford's 2014 PCM code table lists the code as well. Unlike P2290, which watches the running engine, P2291 covers only the start phase.

Likely causes

Leak in the high-pressure oil (HEUI) or fuel (common rail) circuit
Injection pressure regulator or rail pressure valve not sealing
High-pressure pump delivering too little at cranking speed
Low cranking speed from a weak battery or starter

Symptoms

  • Engine cranks long or does not start
  • Starts only after repeated attempts
  • Check engine light after the start attempt

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–2,500
Time1–8 h

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

Parts involved

injection pressure regulatorhigh pressure oil pump

Related codes

P2290P2284P2288P00C6P0087

References: fordservicecontent.com, en.wikipedia.org, performanceparts.ford.com.