Injector Control Pressure Regulator Circuit Low
The P2624 code means the vehicle's onboard diagnostic system has detected: Injector Control Pressure Regulator Circuit Low. This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- hard
- Estimated cost
- $200 - $1200 (parts and labor)
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Common Symptoms
- Low injection control pressure
- Engine cranks but barely starts
- Heavy white smoke on startup
- Loss of power under acceleration
Probable Causes (Ranked by Likelihood)
- IPR valve stuck open dumping pressure Very High
- Short to ground in IPR control wiring High
- High-pressure oil leak in HEUI system Moderate
- Worn high-pressure oil pump Low
Frequently Asked Questions
Can a stuck-open IPR cause white smoke?
Yes. Low injection pressure causes poor fuel atomization, resulting in incomplete combustion and heavy white smoke, especially during cold starts.
What is the HEUI system?
Hydraulic Electronic Unit Injection uses high-pressure engine oil to actuate fuel injectors. The system requires 500-3000+ PSI oil pressure to properly fire injectors.
How much oil pressure does the HEUI system need?
The system typically needs a minimum of 500 PSI ICP for starting and up to 3000+ PSI under full load. P2624 indicates the IPR cannot maintain these pressures.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Monitor ICP pressure during cranking and idle
-
Test IPR valve for proper sealing
-
Check IPR circuit for short to ground
-
Perform high-pressure oil system leak-down test
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2003-2010 Ford F-250 6.0L Diesel
- 2008-2018 Ford F-350 6.4L Diesel
- 2011-2019 Ford F-250 6.7L Diesel
- 2005-2010 Ford F-550 6.0L Diesel
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