P2623
Injector Control Pressure Regulator Circuit/Open
Fuel injection (diesel HEUI)
Generic OBD-II
High
What it means
P2623 means the PCM detected an open in the circuit for the injection control pressure (IPR) regulator. On diesel HEUI-style systems the IPR valve controls the high-pressure oil that actuates the fuel injectors, so a fault here directly affects the engine's ability to start and run. Expect hard starting, stalling, or a no-start until it is repaired.
High
Can I keep driving? Often not — the IPR valve controls the high-pressure oil that fires the injectors, so a fault can cause hard starting, no-start, or stalling.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting, extended cranking, or no-start
- Rough running, surging, or stalling
- Loss of power and heavy exhaust smoke
Common causes
Most likely first
- Open circuit or broken wiring to the injection control pressure (IPR) regulatorLikely
- Corroded or loose connector at the IPR valveCommon
- Failed or stuck IPR regulator valveCommon
- Contaminated high-pressure oil affecting the regulatorLess often
- Faulty PCM driver circuit (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for related injection-control-pressure codes.
- Inspect the IPR connector and harness for opens, corrosion, or chafing.
- Measure the IPR solenoid resistance and check supply and ground.
- Compare commanded versus actual injection control pressure with a scan tool.
- Replace the IPR valve if it fails electrically or hydraulically; otherwise repair the wiring. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2623?+
Not really. Because the IPR regulator controls the oil pressure that fires the injectors, this code can leave you stranded with a no-start or stall. Get it diagnosed before relying on the vehicle.
Can I just clear P2623?+
It will come back, and the running problems will continue, until the IPR valve or its wiring is repaired. Clearing does not restore injection control pressure.
Related codes
Read & clear P2623 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX