P1574 — 8 documented meanings by make

P1574 does not mean the same thing on every car — manufacturers reuse the number for different faults. 13 makes document it: Audi, Chevrolet (USA), Citroen, Ford, Jaguar, Mazda, Nissan, Opel / Vauxhall, Peugeot, SEAT, Skoda, Subaru, Volkswagen. Find your make below.

P1574 on Audi, SEAT, Skoda, Volkswagen

On Audi, SEAT, Skoda, Volkswagen vehicles P1574 is documented as: Left electrohydraulic engine mounting solenoid, N144, electrical failure. P1574 is stored when the ECU sees malfunction on the circuit named in the code (left). 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: Wiring or connector fault in the circuit; Component failed electrically; Supply or ground problem feeding the circuit; Controlling module fault, though this is the least common of the four.

Check first, cheapest first:

1. Read all stored codes — a general fault code is often the symptom of a more specific one
2. Inspect the connector and wiring for the named component
3. Check supply and ground at the component
4. Measure the component against specification
5. Replace the component once wiring and supply are ruled out

Related Audi, SEAT, Skoda, Volkswagen codes:

P1574 on Chevrolet (USA)

On Chevrolet (USA) vehicles P1574 is documented as: EBTCM system/brake light circuit, high voltage. P1574 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 Chevrolet (USA) codes:

P1574 on Citroen, Jaguar, Peugeot

On Citroen, Jaguar, Peugeot vehicles P1574 is documented as: Throttle position sensor disagreement between sensors. P1574 points at throttle body or pedal position. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Citroen, Jaguar, Peugeot codes:

P1574 on Ford

On Ford vehicles P1574 is documented as: Throttle position sensor outputs disagree. P1574 points at throttle body or pedal position. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Ford codes:

P1574 on Mazda

On Mazda vehicles P1574 is documented as: Throttle position sensor output incongruent. P1574 points at throttle body or pedal position. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Mazda codes:

P1574 on Nissan

On Nissan vehicles P1574 is documented as: ASCD vehicle speed sensor. P1574 points at vehicle speed signal. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Nissan codes:

P1574 on Opel / Vauxhall

On Opel / Vauxhall vehicles P1574 is documented as: Brake light switch circuit, incorrect signal. P1574 is stored when the ECU sees range or performance on brake switch. 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 Opel / Vauxhall codes:

P1574 on Subaru

On Subaru vehicles P1574 is documented as: Key communication. P1574 points at immobiliser / key. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Subaru 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 P1574 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.