What does it mean?
P1341 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Ignition Coil Power Output Stage 1 Short to Ground .
Symptoms
- Misfire on the cylinder or cylinder pair fed by that coil, felt as shaking at idle
- Check engine light on, and flashing during heavy misfire
- Loss of power and hesitation when accelerating
- Smell of unburnt fuel from the exhaust, with a risk of catalytic converter damage
- Hard starting and unstable idle when cold
Likely causes
- Coil control wire chafed against the cylinder head, a bracket or a metal clip and grounded
- Internally shorted primary winding in the coil served by output stage 1
- Moisture or oil in the coil connector bridging the control pin to ground
- Harness insulation melted where it runs close to the exhaust manifold
- Coil connector terminals corroded or spread, touching the coil housing
- Damaged output driver inside the control module, often the result of an earlier unrepaired short
- Incorrect coil fitted with a primary resistance far below specification, overloading the driver
How to fix it
- Identify which coil belongs to output stage 1 using the wiring information for the engine, then start at that coil
- Unplug the coil and inspect the connector and boot for oil, water, carbon tracking and corroded terminals
- With the coil unplugged and the key off, measure resistance from the control wire to ground; a very low value confirms the short
- Measure the coil primary winding resistance and compare it with the other coils on the engine
- Follow the control wire from the coil to the module, looking for chafe points, melted insulation and pinched sections
- Repair the harness first, because installing a new module or coil into an existing short will damage it again
- Replace the coil if it is internally shorted, and only consider the module after the coil and wiring are proven good