What it means
The cylinder 4 alternative-fuel injector control circuit has a range or performance fault. The code does not specify current ramp, dwell, peak voltage, or a particular cause.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The alternative-fuel injector for cylinder 4 meters CNG, LPG, or hydrogen into that cylinder on a bi-fuel vehicle, and has a dedicated control circuit. This code is set when the circuit's electrical behaviour falls outside the expected range or performance, without specifying whether the injector, wiring, or module driver is at fault.
Common causes
Most likely first.
- Alternative-fuel injector fault
- Wiring or connector fault
- Control-module driver fault
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
How to diagnose it
- Check freeze-frame data, alternative-fuel mode status, and cylinder-specific misfire counts to establish when cylinder 4's circuit fault occurs.
- Inspect the cylinder 4 injector and its connector for physical damage, loose or corroded terminals, and signs of heat or fuel contamination.
- Examine the cylinder 4 injector harness along its route for chafing, pinching, broken conductors, or poor connections at the module.
- Measure injector winding continuity and circuit voltage or current using the manufacturer's procedure, comparing results with its specifications and other equivalent circuits if permitted.
- If the injector and wiring pass, test the control-module driver and its connector for an intermittent or degraded output.
Common fixes
- Clean and secure the cylinder 4 injector connector or replace damaged terminals.
- Repair damaged or poorly routed cylinder 4 injector wiring.
- Replace the cylinder 4 alternative-fuel injector if it fails the manufacturer's electrical or functional tests.
- Repair or replace the control module if its cylinder 4 driver is confirmed to be out of range.
Can I keep driving?
Avoid alternative-fuel operation if cylinder 4 is misfiring; use another fuel mode only if the vehicle runs smoothly and the manufacturer permits it. Prolonged misfire can increase emissions and damage the catalytic converter; stop if fuel odour or smoke appears.
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.