Diesel Trouble Codes

P2623 — Injector Control Pressure Regulator Circuit/Open — 6.0 Power Stroke

P2623 on a 6.0L Power Stroke means the PCM has detected an open or fault in the IPR control circuit. The IPR valve sits on the high-pressure oil pump in the…

Updated October 15, 2026

What it means

Generic definition: The PCM has detected an open or fault in the injection pressure regulator (IPR) control circuit. Platform note: On the 6.0L the IPR valve sits on the high-pressure oil pump in the engine valley; check the IPR coil resistance, connector and harness before condemning the PCM.1

Most likely causes

  1. IPR valve coil open or shorted — The IPR solenoid coil has failed electrically, so the PCM cannot command pressure. Typical on this platform: On the 6.0L the IPR valve sits on the high-pressure oil pump in the engine valley; check the IPR coil resistance, connector and harness before condemning the PCM.1
  2. IPR connector or harness open/shorted to ground or power — Corrosion, oil intrusion, chafing or loose pins at the IPR connector or in the engine-valley harness create an open or short in the control circuit.1
  3. PCM IPR driver fault — Internal PCM driver for the IPR circuit has failed. This is less common than wiring/IPR faults and should be considered after confirming coil resistance and harness integrity.1

How to diagnose

  1. Verify code and freeze frame; confirm symptoms consistent with HEUI pressure control loss such as hard/no start, stalling, low power, surge. Related ICP/IPR codes: P2284/P2285/P2286 (ICP sensor) and P2290/P2291 (ICP too low while running / cranking).
  2. Inspect IPR valve connector in the engine valley for oil intrusion, corrosion, backed-out pins, and harness chafing.
  3. Measure IPR solenoid coil resistance at the valve connector and compare to spec; an open or out-of-range reading indicates a failed IPR.
  4. Check IPR control circuit continuity from PCM to IPR connector and inspect for shorts to ground or battery voltage; repair wiring as needed.
  5. If coil and wiring test good, evaluate PCM IPR driver output with a scan tool bi-directional command or scope; persistent circuit fault with good external components points to PCM.

Specs and test values

CheckNormal readingWhen to measureSource
ICP while cranking, engine warmShould reach 500–600+ psi; IPR at 85% with low ICP points to a high-pressure oil leakCranking, read on a scan toolBulletproof Diesel

Common mistake to avoid

Replacing the ICP sensor or HPOP when the real problem is a high-pressure oil leak. If ICP stays low while the IPR is commanded hard during cranking, look for leaks at the STC fitting, standpipes, dummy plugs and injector seals before buying parts. Source: Bulletproof Diesel — 6.0L high-pressure oil system diagnostic.

Parts and tools you may need

Tools you’ll need

Rough cost and difficulty

Likely repairPartsShop laborWho usually does it
Wiring or connector repair$10–$1001–4 hrsDIY with tools and a manual
IPR (injection pressure regulator) valve$100–$3001–4 hrsDIY with tools and a manual
ECM/PCM replacement (programmed)$600–$2,0001–3 hrsShop

Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

If the IPR circuit tests good but injection control pressure remains low, high-pressure oil leaks such as the STC fitting, branch tubes/standpipes/dummy plugs, or a worn HPOP may be present. These require specialized testing and safe high-pressure oil handling. Seek a qualified diesel technician.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources

  1. Curated DTC seed — 6.0 Power Stroke (curated) ↩︎ ↩︎ ↩︎ ↩︎