P2291 — Injector Control Pressure Too Low - Engine Cranking — 6.0 Power Stroke

Diagnostic reference for 6.0 Power Stroke (2003.5–2007) P2291.

Updated October 15, 2026

What it means

Generic definition: Injection control pressure does not reach the minimum needed to fire the injectors while the engine is cranking. On 6.0 Power Stroke this is a classic crank-no-start condition where the HPOP cannot build enough oil pressure to fire the injectors.¹

Most likely causes

1. High-pressure oil leak at STC fitting, standpipes, dummy plugs or branch tubes preventing ICP buildup during cranking — A leak in the high-pressure oil circuit bleeds pressure before injectors can fire, typical on 6.0L crank-no-start.¹²
2. Faulty or sticking Injection Pressure Regulator (IPR) valve — IPR controls HPOP output; a stuck or failing valve can keep ICP low during cranking.¹²
3. Worn or failing high-pressure oil pump (HPOP) — Reduced pump output cannot generate required cranking ICP.¹
4. Low engine oil level or aerated oil — Insufficient or aerated oil reduces HPOP prime and ICP buildup.²
5. ICP sensor or connector fault giving false low reading — Oil-contaminated ICP connector or sensor circuit fault can report low pressure even if mechanical pressure is present.³

How to diagnose

1. Verify engine oil level and condition; correct low/aerated oil before further tests.
2. Monitor ICP pressure with a scan tool while cranking; compare to expected cranking pressure threshold.
3. Command IPR duty cycle and observe ICP response to assess IPR control authority.
4. Inspect ICP sensor connector for oil contamination and check 5 V reference and signal integrity.
5. Perform high-pressure oil system leak test (air test) to identify leaks at STC fitting, standpipes, dummy plugs, branch tubes.
6. Check HPOP output and condition if no external leaks are found and IPR commands are normal.

Specs and test values

Common mistake to avoid

Replacing the ICP sensor or HPOP when the real problem is a high-pressure oil leak. If ICP stays low while the IPR is commanded hard during cranking, look for leaks at the STC fitting, standpipes, dummy plugs and injector seals before buying parts. Source: Bulletproof Diesel — 6.0L high-pressure oil system diagnostic.

Parts and tools you may need

• Scan tool with live ICP/IPR data
• Digital multimeter
• High-pressure oil system air test kit
• Basic hand tools for inspection

Tools you’ll need

• OBD-II scan tool — Reads live ICP pressure and IPR duty cycle while cranking to confirm the pressure does not reach the start threshold.
• digital multimeter — Checks ICP sensor 5 V reference, signal integrity, and connector oil contamination that can cause false low pressure readings.
• air pressure tester — Performs a high-pressure oil system air test to locate leaks at STC fitting, standpipes, dummy plugs, or branch tubes.

Rough cost and difficulty

Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

If diagnosis indicates internal high-pressure oil leak or HPOP failure, have a qualified diesel technician perform verification and repair. Do not attempt high-pressure oil system service without proper training and safety equipment.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources