What it means
Cylinder 1 Injector Circuit High: the signal voltage is above the expected range. This affects fueling of the associated cylinders.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The engine control module switches and monitors the injector circuit for cylinder 1, which meters fuel into that cylinder. P0262 sets when the circuit signal is higher than expected, often because the wiring is shorted to a supply or the circuit connection is faulty.
Common causes
Most likely first.
- Injector circuit shorted to supply
- Wiring or connector fault
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light on
- Rough running or misfire
- Reduced engine power
- Hard starting
How to diagnose it
- Save freeze-frame data and check cylinder 1 misfire counts and injector command data to confirm the affected cylinder and operating conditions.
- Inspect the cylinder 1 injector connector and harness for wiring damage, loose terminals, corrosion, or contact with a power feed.
- Test the cylinder 1 injector control wire for a short to supply using the manufacturer's wiring diagram and procedure.
- Check the cylinder 1 injector winding and circuit continuity against the manufacturer's specifications.
- If the injector and harness pass, test the cylinder 1 injector driver circuit at the engine control module.
Common fixes
- Repair wiring in the cylinder 1 injector circuit that is shorted to a supply.
- Clean or replace loose or corroded injector connector terminals.
- Replace the cylinder 1 injector if it fails the specified electrical test.
- Repair the injector driver circuit if module-side testing confirms a fault.
Can I keep driving?
Cylinder 1 may misfire or receive incorrect fueling, reducing power and potentially damaging the catalytic converter. Avoid hard acceleration and stop if the engine runs severely rough or the warning light flashes.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.