P1422 — 4 documented meanings by make

P1422 does not mean the same thing on every car — manufacturers reuse the number for different faults. 9 makes document it: Audi, Citroen, Ford, Mazda, Peugeot, SEAT, Skoda, Subaru, Volkswagen. Find your make below.

P1422 on Audi, SEAT, Skoda, Volkswagen

On Audi, SEAT, Skoda, Volkswagen vehicles P1422 is documented as: Secondary air inlet valve, N112, short circuit to positive. P1422 is stored when the ECU sees short to positive on secondary air injection. 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: Signal wire touching a permanently live wire in a damaged loom; Connector pins bridged by corrosion or a bent terminal; Internal fault in the component shorting the signal to supply; Incorrect wiring after an aftermarket accessory was fitted.

Check first, cheapest first:

1. Disconnect the component and check whether the signal line still reads battery voltage
2. Inspect the loom for melted or rubbed insulation, especially near heat sources
3. Check the connector for a pushed-back or bent terminal
4. Trace the signal wire back to the module, looking for a live wire running alongside
5. Repair the harness, or replace the component if it is shorting internally

Related Audi, SEAT, Skoda, Volkswagen codes:

P1422 on Citroen, Peugeot

On Citroen, Peugeot vehicles P1422 is documented as: EGI temperature sensor failure. P1422 is stored when the ECU sees malfunction 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: 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 Citroen, Peugeot codes:

P1422 on Ford, Mazda

On Ford, Mazda vehicles P1422 is documented as: Exhaust gas ignition temperature sensor.

Related Ford, Mazda codes:

P1422 on Subaru

On Subaru vehicles P1422 is documented as: Evaporative emission system purge control valve circuit high input. P1422 is stored when the ECU sees signal too high on evaporative emissions 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: 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 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 P1422 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.