OBD2 P2291

Severity

Summary

P2291 indicates that the injector control pressure in the high-pressure fuel system is too low during engine cranking, which can prevent the engine from starting. This issue typically affects Ford Powerstroke engines built between 2011 and 2016.

Symptoms

• Engine cranks but does not start
• Excessive black or white smoke from tailpipe if the engine starts
• Vehicle may be locked in fail-safe mode

Common Causes

• Failed high-pressure fuel pump
• Defective pressure switch in low-pressure fuel system
• Malfunctioning high-pressure fuel pressure regulator
• Blocked or restricted fuel filters
• Fuel escaping from injectors at an excessive rate
• Insufficient backpressure in the return line

Diagnosis

1. Measure fuel pressure in rails during cranking or idling using a scan tool or gauge
2. Check low-pressure fuel system for proper pressure and filter condition
3. Verify injector return flow rate and backpressure
4. Consider high-pressure pump failure if other causes are ruled out

Fixes

• Replace faulty components such as the high-pressure fuel pump, pressure switch, or injectors— $1000+ for a new high-pressure fuel pump and additional labor costs

FAQ