P1263 Code: Cylinder 3 Fuel Injector Circuit Short (High to Low)
🟠 Moderate severity · drivable
Drivable, but the engine will run rough — fix it soon so the misfire does not damage the catalytic converter.
What P1263 means
The engine computer found an electrical short between the high-side and low-side circuits that fire the fuel injector for cylinder 3. That short usually means the injector is damaged or its wiring is rubbed bare, so the injector may not fire correctly and the cylinder misfires. This code is most common on Ford diesel trucks.
Symptoms
- Check engine light is on, possibly flashing
- Rough idle or misfire on cylinder 3
- Loss of power or hesitation
- Poor fuel economy
Common causes
- most common: Damaged injector with an internal short
- common: Chafed or shorted wiring in the injector harness
- common: Corroded or loose injector connector
- less common: Faulty engine computer
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Inspect the injector connector and wiring for damage | Yes | $0–50 |
| Test the injector resistance with a multimeter | Yes | $10–50 |
| Repair or replace the damaged injector wiring | Yes | $50–200 |
| Replace the fuel injector for cylinder 3 | Mechanic | $200–600 |
Frequently asked questions
Can I drive with a P1263 code?
Yes, but the engine will run rough, and a misfire can damage the catalytic converter over time, so fix it soon.
What does a high to low side short mean?
It means the two electrical circuits that power the fuel injector are touching each other, usually from a damaged injector or bare wiring.
How much does it cost to fix a P1263?
Wiring or connector repairs usually run $50–$200. Replacing the fuel injector costs $200–$600.
Related codes
P1262
P1262 Code: Cylinder 2 Fuel Injector Circuit Short (High to Low)
P0265P0265 Code: Cylinder 2 Injector Circuit High
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.