What does it mean?
P1343 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Ignition Coil Power Output Stage 2 Short to Ground .
Symptoms
- Persistent misfire on the affected cylinder group with obvious vibration at idle
- Check engine light on, often flashing under load
- Engine feels down on power and hesitates when pulling away
- Fuel smell from the tailpipe and rising fuel consumption
- Rough, uneven running that gets worse in wet weather if moisture is involved
Likely causes
- Grounded coil control wire, typically where the harness passes a sharp bracket edge or a loose clip
- Coil on that output with a shorted primary winding drawing far more current than designed
- Water sitting in the coil connector after washing or a leaking cowl seal
- Harness rubbing on the valve cover or a coolant pipe until the copper is exposed
- Melted section of harness near a hot exhaust component
- Output driver in the module already damaged by the short circuit
- Aftermarket wiring or a previous repair splice that has failed and grounded out
How to fix it
- Determine which cylinder or cylinder pair output stage 2 serves before touching any parts
- Inspect the coil connector, boot and harness for water, oil, chafing and terminal damage
- Disconnect the coil and measure resistance from the control wire to ground; a near-zero reading proves the short
- Compare the primary resistance of the suspect coil against a known-good coil on the same engine
- Trace the full length of the control wire and repair any chafed or melted section properly, with heat-resistant protection
- Clear the code and recheck with live data or a test light before deciding the module is at fault
- Replace the shorted coil, and if the module driver was damaged, repair the harness fault first so the new driver survives