A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
Possible causes
- The sensor shows implausible values
- Sensor connector or wiring: corrosion, an open circuit, a chafed wire
- The sensor itself
What you can do yourself
- The sensor sits in the exhaust ahead of the turbo, catalyst or particulate filter. Check the connector: heat makes it corrode.
- Check the sensor number (1, 2) and the bank on your car’s wiring diagram: sensor 1 is usually closer to the engine.
- While the sensor is faulty, the ECU may not start cleaning (regenerating) the particulate filter, so the filter will clog faster. Don’t put off the repair.
- The ECU may limit power to protect the turbo and the particulate filter.
Stop and don’t drive on if:
- The Check Engine light is flashing
- The temperature gauge is in the red or the overheating light is on
- The red oil pressure light is on
- Smoke from under the bonnet, a burning or petrol smell
- Strong jerking, knocking from the engine, or the car barely moves
OOleg’s tip: check the connector
Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.
Unplug and inspect connectors with the ignition off.
Find the part on Kaspi ShopBefore buying, check the part number or match the part by VIN in the Kaspi “Garage”.
The explanation comes from the error code reference in the AvtoElektrik PRO app.