P1305 — 9 documented meanings by make

P1305 does not mean the same thing on every car — manufacturers reuse the number for different faults. 14 makes document it: Audi, Chevrolet (USA), Citroen, Ford, Honda, Lexus, Mazda, Nissan, Peugeot, Saab, SEAT, Skoda, Toyota, Volkswagen. Find your make below.

P1305 on Audi, SEAT, Skoda, Volkswagen

On Audi, SEAT, Skoda, Volkswagen vehicles P1305 is documented as: Ignition circuit, cylinder 9, open circuit. P1305 is stored when the ECU sees open circuit on ignition coil or spark circuit (cylinder 9). 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: Broken wire, most often at a flex point such as a door hinge or engine mount; Corroded or pushed-back terminal in the connector; Blown fuse on the supply side; Component failed with an internally open winding or element.

Check first, cheapest first:

1. Check the relevant fuse first — it is the cheapest thing that produces this code
2. Unplug and inspect both halves of the connector for corrosion and terminal fit
3. Continuity-test the wire end to end while flexing the loom by hand
4. Measure the component itself against its specification
5. Repair the break or replace the component, whichever the measurement points to

Related Audi, SEAT, Skoda, Volkswagen codes:

P1305 on Chevrolet (USA)

On Chevrolet (USA) vehicles P1305 is documented as: Ignition coil 2 primary feedback circuit. P1305 points at ignition coil or spark circuit. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Chevrolet (USA) codes:

P1305 on Citroen, Peugeot

On Citroen, Peugeot vehicles P1305 is documented as: EGR calibration low. P1305 is stored when the ECU sees signal too low on EGR system. 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: High resistance in the supply or ground path, dragging the signal down; Corroded connector adding resistance the module reads as a low reading; Sensor drifted out of tolerance with age; Partial short to ground somewhere in the signal line.

Check first, cheapest first:

1. Read the live value on a scanner and compare with a known-good reading
2. Clean and re-seat the connector, then re-test before replacing anything
3. Check the ground point for that circuit — a poor ground causes this far more often than a bad sensor
4. Measure the sensor against specification with the connector back-probed
5. Replace the sensor only once the wiring and ground have been ruled out

Related Citroen, Peugeot codes:

P1305 on Ford, Mazda

On Ford, Mazda vehicles P1305 is documented as: Exhaust gas recirculation calibration low. P1305 is stored when the ECU sees signal too low on EGR system. 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: High resistance in the supply or ground path, dragging the signal down; Corroded connector adding resistance the module reads as a low reading; Sensor drifted out of tolerance with age; Partial short to ground somewhere in the signal line.

Check first, cheapest first:

1. Read the live value on a scanner and compare with a known-good reading
2. Clean and re-seat the connector, then re-test before replacing anything
3. Check the ground point for that circuit — a poor ground causes this far more often than a bad sensor
4. Measure the sensor against specification with the connector back-probed
5. Replace the sensor only once the wiring and ground have been ruled out

Related Ford, Mazda codes:

P1305 on Honda

On Honda vehicles P1305 is documented as: Cylinder 5 misfire. P1305 points at engine misfire (cylinder 5). 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 Honda codes:

P1305 on Lexus

On Lexus vehicles P1305 is documented as: Igniter circuit (bank 2 or nr. 2).

Related Lexus codes:

P1305 on Nissan

On Nissan vehicles P1305 is documented as: Fuel leak, relation between output signal to suction control valve and input signal to common railfuel rail pressure sensor out of range. P1305 is stored when the ECU sees range or performance on fuel supply. 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: Sensor reading is inside its electrical range but does not match reality; Contamination or deposits changing what the sensor sees; A mechanical fault upstream that the sensor is correctly reporting; Sensor drifted with age without failing outright.

Check first, cheapest first:

1. Compare the live value against a second sensor or a known-good figure — this code is about plausibility, not a dead circuit
2. Look for the mechanical cause first: leaks, restrictions or wear that would genuinely produce this reading
3. Clean the sensor if it is the type that fouls
4. Check freeze-frame data to see under what conditions it triggered
5. Replace the sensor only after the mechanical side is ruled out

Related Nissan codes:

P1305 on Saab

On Saab vehicles P1305 is documented as: Cylinder 5 misfire detected, catalyst damaging. P1305 points at engine misfire (cylinder 5). 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 Saab codes:

P1305 on Toyota

On Toyota vehicles P1305 is documented as: Ignition coil with igniter nr. 2. P1305 points at ignition coil or spark circuit. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Toyota 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 P1305 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.