What it means
Ignition I control signal stuck high — short to B+. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The PCM sends the ignition I control signal to operate the corresponding ignition coil group. This code sets when the circuit stays higher than expected, which can occur if the control wire is shorted to battery power or has a faulty connection.
Common causes
Most likely first.
- Short to B+
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check engine light on
- Hard starting or no-start
- Engine may misfire or run roughly
- Reduced engine performance
How to diagnose it
- Review freeze-frame data and ignition or misfire live data to determine when the ignition I control circuit is high and whether engine operation changes.
- Inspect ignition I wiring and connectors for a pinched wire touching a power source, corrosion, moisture, or loose terminals.
- With the circuit active, gently move accessible harness sections while monitoring live data for a change that helps locate an intermittent short.
- Use the wiring diagram to test the ignition I control wire for an unintended connection to battery positive, following the manufacturer's procedure.
- If the wiring and connectors pass, test the ignition I coil group and PCM control output according to the manufacturer's diagnostic procedure.
Common fixes
- Repair wiring pinched against a power source in the ignition I control circuit.
- Clean or repair corroded connectors and secure loose terminals.
- Repair a confirmed fault in the ignition I coil group.
- Repair the PCM only if its control output is confirmed faulty.
Can I keep driving?
A high ignition I control signal can cause misfiring, reduced power, or a no-start. Avoid hard acceleration and stop driving if the engine runs severely unevenly or stalls.
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.