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
Often seen with P2623
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