P0205 — Injector Circuit/Open - Cylinder 5 — 5.9 Cummins Common Rail
The ECM has detected an electrical fault in the injector circuit for cylinder 5 on a 5.9L Cummins Common Rail 2003-2007.
What it means
The engine control module has detected an electrical fault in the injector circuit for cylinder 5. On this platform injectors are Bosch common-rail solenoid type and electrical faults show as P0201-P0206; contribution/balance issues show as P0263-family.123
Most likely causes
- Open or high resistance in cylinder 5 injector harness/connectors — Inspect the injector connector and engine harness for corrosion, backed-out pins, chafing or oil intrusion at the valve cover pass-through. Check continuity from ECM to injector and look for intermittent opens that set P0205.123
- Failed cylinder 5 injector solenoid/electrical coil — A failed injector solenoid or internal open in the injector coil will set an injector circuit/open code for that cylinder. Compare resistance to spec and to other cylinders.123
- ECM driver fault for cylinder 5 injector — Internal ECM injector driver failure can cause a circuit/open detection for a single cylinder. Verify wiring first; if wiring and injector test good, suspect ECM.123
How to diagnose
- Verify code P0205 is present and check for additional injector codes P0201-P0206.
- Inspect cylinder 5 injector connector, terminals and harness for damage, corrosion or oil contamination; repair as needed.
- Measure injector solenoid resistance at the injector connector and compare to other cylinders; look for open or out-of-spec reading.
- Perform a continuity and isolation check of the injector wiring from ECM connector to injector connector; wiggle test harness while monitoring.
- If wiring and injector test good, evaluate ECM injector driver output with a scope or scan tool bi-directional test; consider ECM if fault persists.
Parts and tools you may need
- Digital multimeter
- Scan tool with live data and bi-directional control
- Wiring diagram for 2003-2007 5.9L Cummins Common Rail
- Terminal release tools
- Dielectric grease
- Replacement injector pigtail/harness as needed
Tools you’ll need
- digital multimeter — Measures injector solenoid resistance and wiring continuity to isolate open/high-resistance faults in cylinder 5 circuit.
- OBD-II scan tool — Confirms P0205 presence, checks for related P0201-P0206 codes, and enables bi-directional injector tests for ECM driver evaluation.
- inspection light — Provides clear illumination for inspecting cylinder 5 injector connector, terminals, and harness for damage, corrosion, or oil contamination.
- oscilloscope — Captures ECM injector driver waveform to verify proper switching and identify driver faults when wiring and injector test good.
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 injector (each) | $300–$600 | 1–2 hrs | Shop |
| 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 good and injector resistance is normal but P0205 returns, have the ECM evaluated by a qualified diesel technician. Do not attempt high-pressure fuel system service. If drivability is affected, stop driving and seek professional diagnosis.
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: P0205 on the 5.9 Cummins CR
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
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