What does it mean?
P1345 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Ignition Coil Power Output Stage 3 Short to Ground .
Symptoms
- Dead or weak cylinder with the engine shaking noticeably at idle
- Check engine light on and often flashing under acceleration
- Reduced power, poor throttle response and a stumble when pulling away
- Strong exhaust smell of unburnt fuel and rising consumption
- In severe cases the engine runs on fewer cylinders and vibrates at all speeds
Likely causes
- Control wire for that coil grounded through chafed insulation or a trapped harness section
- Coil with a shorted primary winding on the cylinder served by output stage 3
- Contaminated coil connector, with oil from a leaking valve cover gasket bridging the pins
- Terminal pushed back in the connector and touching the coil body or the head
- Harness damage from vibration where the coil leads cross the engine
- Module output driver already damaged by the ground fault
- A coil of the wrong specification fitted during a previous repair
How to fix it
- Identify the cylinder served by output stage 3 from the engine's wiring layout before removing parts
- Inspect that coil, its boot, connector and spark plug for oil, water, cracks and carbon tracking
- Unplug the coil and check for a short between the control wire and ground with the key off
- Measure and compare primary winding resistance across all coils to isolate the shorted one
- Follow the control wire toward the module, checking clips, brackets and any earlier repair splices
- Fix the wiring fault before fitting a new coil, so the replacement is not damaged by the same short
- Replace the faulty coil and, if the driver inside the module has failed, address the module only after the circuit is confirmed clean