What does it mean?
P1230 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 6 Fuel Injection Circuit Short to Ground .
Symptoms
- Check engine lamp on with misfire recorded on cylinder 6
- Rough idle, uneven running and a loss of smoothness under load
- Rich mixture, black smoke and a strong smell of fuel
- Fuel in the oil and a wet, sooty plug on that cylinder
- Hard starting, or no start at all if the injector fuse has blown
Likely causes
- Worn insulation where the wire is clipped against the engine or a metal channel
- Coolant or water in the injector connector creating a path to earth
- Injector shorted internally between winding and body
- Harness pinched during intake or cover removal and refitting
- Vibration damage at a fixing point that has cut into the loom
- Injector driver in the module already destroyed by the short
How to fix it
- Check the injector fuse and note which cylinders it feeds
- Unplug the injector and measure resistance from control wire to ground to confirm the short
- Inspect the loom at every clip, bracket and channel it passes through
- Look for coolant and corrosion in the connector and test the injector pins against the body
- Compare injector resistance readings across all cylinders
- Repair the harness and secure it away from metal, then recheck the circuit
- Replace the injector if it tests shorted and evaluate the module driver only afterwards