P0262 — Cylinder 1 Injector Circuit High — 7.3 Power Stroke
P0262 is a per-cylinder injector circuit fault on the 7.3L Power Stroke HEUI system. The PCM/IDM has detected abnormally high voltage/current in the cylinder 1…
What it means
The engine control module has detected an abnormally high voltage or current in the injector circuit for cylinder 1. On the 7.3L Power Stroke this is a HEUI, IDM-driven injector circuit fault, not a common-rail pressure issue.1
Most likely causes
- Open or high-resistance in the cylinder 1 injector control circuit (IDM output to injector). — The IDM drives the HEUI injectors; an open, corroded, or oil-soaked connection raises circuit voltage/current seen by the PCM/IDM. Per-cylinder injector circuit faults are P0261/P0262 for cylinder 1 on this platform.12
- Under-Valve-Cover Harness (UVCH) failure at cylinder 1. — The UVCH connectors and pigtails under the valve cover are a known failure point on 7.3L Power Stroke, often oil-soaked or chafed, causing injector and glow-plug circuit codes.2
- Faulty or damaged cylinder 1 injector solenoid/electrical connector. — A failed injector electrical element or damaged connector can present as high circuit voltage/current to the IDM/PCM.1
- Injector Driver Module (IDM) output fault for cylinder 1. — The IDM is a separate module on the driver-side fender that drives the injectors; an internal output fault can set a per-cylinder high circuit code. IDM/output-circuit faults are P1660, P1662, P1663 on this platform.2
- PCM detection/wiring issue between PCM and IDM for cylinder 1 control. — Wiring, connectors, or PCM input processing can cause the PCM to read abnormally high voltage/current on the cylinder 1 injector circuit.1
How to diagnose
- Verify code and freeze-frame; confirm P0262 is present and not accompanied by ICP/IPR or IDM codes.
- Inspect IDM power/ground and main engine harness connectors for corrosion, oil contamination, or loose pins.
- Check UVCH at cylinder 1 for oil intrusion, chafing, or damaged pins; inspect injector connector and pigtail under valve cover.
- Perform electrical tests of the cylinder 1 injector control circuit resistance/continuity from IDM connector to injector, comparing to other cylinders.
- Inspect IDM and its connectors for moisture/oil; verify IDM power/ground integrity.
- If circuit tests normal, evaluate IDM output behavior and PCM inputs for cylinder 1; compare to known-good values.
- Clear codes and retest after repairs to confirm circuit returns to normal.
- Note: Do not describe this engine as common-rail; 7.3L Power Stroke uses HEUI with HPOP/ICP/IPR, no rail pressure sensor.
Specs and test values
| Check | Normal reading | When to measure | Source |
|---|---|---|---|
| Fuel pressure | 1994–97: 40–70 psi. 1998–2003: never below 30 psi (Ford spec 30–80); 50–60 psi typical at idle | Key on engine off, cranking and idle | DieselHub |
| Battery and charging voltage | 12.6–12.7 V at rest when fully charged; about 13.5 V running | Engine off, then running with loads on | DieselHub |
Parts and tools you may need
- Digital multimeter
- Wiring diagram for 7.3L Power Stroke IDM/injector circuits
- Injector breakout box or IDM test harness
- Dielectric grease
- Replacement UVCH and injector connector pigtails as needed
Tools you’ll need
- digital multimeter — Measures resistance and continuity of the cylinder 1 injector control circuit from IDM to injector and compares values to other cylinders.
- OBD-II scan tool — Reads P0262, freeze-frame data, and monitors IDM/ICP/IPR related codes to confirm the fault is isolated to cylinder 1 injector circuit.
- inspection mirror — Allows visual inspection of the under-valve-cover harness and injector connector at cylinder 1 for oil intrusion, chafing, or damaged pins.
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 |
| Injector wiring harness / under-valve-cover harness | $50–$300 | 2–5 hrs | Shop |
| Fuel injector (each) | $150–$350 | 1.5–4 hrs | Shop |
| IDM (injector driver module), reman | $330–$600 | 1–2 hrs | DIY with tools and a manual |
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 fault persists after UVCH and wiring checks, or if IDM/PCM involvement is suspected, have a diesel technician with 7.3L HEUI experience perform IDM output testing and PCM evaluation. Do not attempt high-pressure oil or injector removal without proper training and safety precautions.
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: P0262 on the 7.3 Power Stroke
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
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