Injector Control Pressure Regulator Circuit Open
The P2623 code means the vehicle's onboard diagnostic system has detected: Injector Control Pressure Regulator Circuit Open. This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- hard
- Estimated cost
- $200 - $800 (parts and labor)
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Common Symptoms
- Diesel engine no-start or hard start
- Loss of injection pressure
- Rough idle and white smoke
- Engine stalls under load
Probable Causes (Ranked by Likelihood)
- Failed injection pressure regulator (IPR) valve Very High
- Open wiring to IPR valve High
- Blown IPR control fuse Moderate
- ECM IPR driver circuit failure Low
Step-by-Step Diagnostic Procedure
-
Test IPR valve coil resistance
-
Check IPR connector and wiring for open circuits
-
Verify IPR control fuse
-
Monitor injection control pressure with scan tool
Frequently Asked Questions
What does the IPR valve do?
The Injection Pressure Regulator controls high-pressure oil that actuates the fuel injectors in HEUI (Hydraulic Electronic Unit Injector) diesel systems used primarily by Ford.
Can I drive without injection control pressure?
No. Without proper ICP (Injection Control Pressure), the injectors cannot fire correctly, and the engine will not run or will run very poorly.
Is the IPR related to the ICP sensor?
They work together. The ICP sensor measures pressure, and the IPR valve regulates it. P2623 is specifically about the IPR control circuit.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P2623 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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