P1348–P1350 Ignition Coil Power Output Stage 1: Open Circuit
The circuit is broken somewhere - a cut wire, a corroded pin or an unplugged connector means the signal never arrives.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P1348 | Ignition Coil Power Output Stage 1: Open Circuit | Investigate soon |
P1349 | Ignition Coil Power Output Stage 2: Open Circuit | Investigate soon |
P1350 | Ignition Coil Power Output Stage 3: Open Circuit | Investigate soon |
The definition
P1348: Ignition Coil Power Output Stage 1: Open Circuit.
P1348 is a manufacturer-specific powertrain code (the engine or gearbox). Its meaning is set by the carmaker rather than by the SAE standard, so a generic OBD-II reader will often show it as an unknown code or misread it.
What to check first
Cheapest and fastest checks first:
- Check the connector is fully seated and the locking tab is engaged. A half-seated plug is the single most common cause of an open circuit.
- Back-probe the pins and check continuity from the part back to the module connector.
- Inspect for a pushed-back or corroded terminal - the wire looks fine but the pin has backed out of the housing.
What actually causes this on a VAG
The power output stage is the ECU's switch for an ignition coil. 'Open circuit' means the ECU sent the command and found nothing connected on the other end - no load, no continuity. Compared with the short-circuit versions of this fault, this one is often the cheapest to fix, because an open circuit is frequently just something not plugged in properly. On most engines with a coil per cylinder, stage 1 is the driver for cylinder 1, though some older engines run one stage for a pair of cylinders. Expect a misfire on that cylinder and a warning light.
Most likely causes, in order
- Coil connector not clicked home. After spark plugs, cam cover, injector or any other top-end work, a coil plug that hasn't fully latched will back off with vibration and heat. Check each coil connector individually - it should click when pushed on and shouldn't pull off with a gentle tug. The retaining clips go brittle with heat and do break, and they're cheap to replace.
- Broken wire or corroded pin. A wire that has fractured inside its insulation, or a pin that has corroded or pushed back out of the connector body, gives exactly this reading. Look closely inside the plug for a pin sitting lower than its neighbours and follow the loom for any section that has been pulled tight or heat-damaged.
- Coil with an open winding. A coil whose primary winding has gone open circuit reports as no load at all. Confirm it the cheap way: swap with the coil from the cylinder next door, clear the code and re-test - if the fault follows the coil, replace it.
- Separate ignition output stage module. On older VAG engines that use a standalone ignition amplifier rather than a driver inside the coil or ECU, the module itself can fail. This only applies to those earlier engines, so check what your car actually has before ordering one.
Worth knowing: Check that every coil connector is properly latched before ordering a single part. On an open-circuit fault the repair is very often a connector that was never pushed fully home during previous work, and it costs nothing to find. If the warning light is flashing rather than steady, stop driving - a misfire that severe can wreck the catalytic converter.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P1348 mean?
P1348 means Ignition Coil Power Output Stage 1: Open Circuit. The circuit is broken somewhere - a cut wire, a corroded pin or an unplugged connector means the signal never arrives.
Can I drive with P1348?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.