P0090 — Fuel Pressure Regulator Control Circuit — 6.7 Cummins (EGR + DPF, pre-SCR)
P0090 means the ECM has detected an electrical fault in the circuit that controls the fuel pressure regulator on a 6.7L Cummins 2007.5–2012 EGR+DPF pre-SCR.
What it means
On this platform the fuel pressure regulator is the Fuel Control Actuator (FCA/MPROP) on the Bosch CP3 high-pressure pump. The ECM monitors the FCA control circuit; P0090 is set for an electrical fault in that control circuit, not a mechanical rail-pressure issue.1
Most likely causes
- FCA/MPROP electrical connector or wiring open/short to ground or power — Inspect the FCA connector at the CP3 pump for corrosion, backed-out pins, chafing, or oil intrusion; check harness continuity and isolation to ground/power. The ECM detects an electrical fault in the fuel pressure regulator control circuit.1
- ECM driver fault for the FCA control circuit — If wiring and FCA coil resistance are normal, the ECM internal driver may be faulty. The generic definition is an electrical fault in the circuit that controls the fuel pressure regulator.1
- FCA/MPROP coil internal open/short — Measure FCA coil resistance per service spec; an out-of-range reading indicates a failed actuator. The code is for the fuel pressure regulator control circuit on the CP3 system.1
How to diagnose
- Verify code P0090 is present and check freeze-frame for engine state.
- Visually inspect CP3 pump FCA connector and harness for damage, oil, corrosion; repair as needed.
- Measure FCA coil resistance at the actuator connector and compare to spec; replace FCA if out of spec.
- Check FCA control circuit wiring for continuity, shorts to ground/power between ECM and FCA; repair wiring if fault found.
- If wiring and FCA are good, perform ECM pin-out tests per service info to confirm ECM driver integrity.
- Clear codes and retest; monitor rail pressure control with scan tool to confirm normal regulation.
Parts and tools you may need
- Digital multimeter
- Scan tool with Cummins enhanced data
- Terminal release tools
- Dielectric grease
- Replacement FCA/MPROP for Bosch CP3
- Wiring repair kit
Tools you’ll need
- digital multimeter — Measures FCA coil resistance and checks continuity/shorts in the FCA control circuit between ECM and actuator.
- OBD-II scan tool — Reads P0090, views freeze-frame data, and monitors rail pressure control after repairs to confirm normal regulation.
- inspection light — Provides clear illumination to inspect the CP3 FCA connector and harness for damage, oil contamination, or corrosion.
- wiring repair kit — Repairs damaged wiring or connector terminals found in the FCA control circuit to restore proper ECM-actuator communication.
Rough cost and difficulty
| Likely repair | Parts | Shop labor | Who usually does it |
|---|---|---|---|
| Wiring or connector repair | $10–$100 | 1–4 hrs | DIY with tools and a manual |
| Fuel pressure control valve (FCA/regulator) | $100–$400 | 0.5–2 hrs | DIY with tools and a manual |
| ECM/PCM replacement (programmed) | $600–$2,000 | 1–3 hrs | Shop |
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 wiring tests pass and FCA tests good but P0090 returns, have the ECM evaluated by a qualified diesel technician. Do not attempt high-pressure fuel system disassembly. If the engine stalls or loses power while driving, stop and tow; sudden loss of power can affect steering/braking assist.
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
Repair videos: P0090 on the 6.7 Cummins '07.5–'12
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
Spotted an error, or something missing? Tell us
Run a 6.7 Cummins (EGR + DPF, pre-SCR)? This goes straight to the editor — it is not published.