P2291 code meaning
Injector Control Pressure Too Low - Engine Cranking
Powertrain system Generic code P22xx codes Check engine light
What P2291 means
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.
P2291 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2291
- Engine cranks long or does not start
- Starts only after repeated attempts
- Check engine light after the start attempt
Common causes of P2291
- Most likelyLeak in the high-pressure oil (HEUI) or fuel (common rail) circuit
- PossibleInjection pressure regulator or rail pressure valve not sealing
- PossibleHigh-pressure pump delivering too little at cranking speed
- Less likelyLow cranking speed from a weak battery or starter
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Injection pressure regulatorHigh pressure oil pump
What each part of P2291 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| 91 | The exact fault in that area. |
What to do next
- Note P2291 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 P2291
What does P2291 mean?
P2291 means "Injector Control Pressure Too Low - Engine Cranking". P2291 judges pressure build-up while the starter is turning. It is a generic code, so it means the same on every make.
Is it safe to drive with P2291?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2291 fail an emissions test?
Yes, it can. P2291 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 P2291 to fix?
Difficulty: hard. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P2291 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.