P1379 — 2 documented meanings by make

P1379 does not mean the same thing on every car — manufacturers reuse the number for different faults. 6 makes document it: Audi, Ford, Mazda, SEAT, Skoda, Volkswagen. Find your make below.

P1379 on Audi, SEAT, Skoda, Volkswagen

On Audi, SEAT, Skoda, Volkswagen vehicles P1379 is documented as: Cylinder 13 misfire detected. P1379 points at engine misfire (cylinder 13). The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Usually one of: Worn or fouled spark plugs; Failed ignition coil on that cylinder; Injector blocked or leaking; Loss of compression — worn valve or head gasket; Unmetered air leaking into the intake.

Check first, cheapest first:

1. Swap the coil with a neighbouring cylinder and see whether the misfire follows it — this identifies a coil fault in minutes and costs nothing
2. Pull the plug on that cylinder and read its condition
3. Swap the injector the same way if the misfire stayed put
4. Check for vacuum leaks around the intake
5. Compression-test the cylinder if the electrical and fuel sides are both good

Related Audi, SEAT, Skoda, Volkswagen codes:

P1379 on Ford, Mazda

On Ford, Mazda vehicles P1379 is documented as: FICM supply voltage circuit high. P1379 is stored when the ECU sees signal too high on the circuit named in the code. That describes how the circuit is behaving, not which part has failed — the wiring, the connector and the component itself can all produce it, which is why the checks below start with the cheapest.

Usually one of: Open ground for the sensor, letting the signal float up; Signal line shorted to a supply voltage; Sensor failed open, which the module reads as maximum; Connector fault interrupting the return path.

Check first, cheapest first:

1. Read the live value and compare with what the conditions should produce
2. Check the sensor ground continuity back to the module
3. Unplug the sensor: if the reading changes, the wiring is intact and the sensor is suspect
4. Inspect the connector for corrosion or a spread terminal
5. Replace the sensor once ground and signal wiring are confirmed good

Related Ford, Mazda codes:

Which one is yours

A generic OBD reader gives you the number, not which of these meanings your manufacturer assigned to it. To get to the specific one:

1. Use a brand-specific scanner — VCDS for VAG, INPA or ISTA for BMW, XENTRY for Mercedes, Forscan for Ford. It shows the manufacturer's own text rather than the generic one.
2. Read all stored codes together — the neighbouring ones usually point at which system is involved and narrow the list.
3. Check freeze-frame data: the RPM, temperature and load at the moment it triggered indicate which system was active.
4. If you have no brand scanner, tell me the make and model below and I will tell you which of these applies to your car.

Code family

P1xxx is manufacturer-specific code (VW/Audi, BMW, Mercedes, Toyota etc. have different meanings for the same code number).

Severity

Manufacturer-specific codes need a brand scanner (VCDS for VAG, INPA for BMW, STAR for Mercedes).

That is what holds for P1379 in general. From here it depends on your engine — tell me which car it is and what it does, and I will give you the steps for it: real procedures, torque figures and diagrams instead of general advice.