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
- Damaged or contaminated NOx sensor
- Damaged sensor wires, terminals or connector
- Exhaust leak
- Rarely — the control unit
What you can do yourself
- Inspect and clean the NOx sensor connector, check the harness
- Fix the exhaust leaks
- After the repair, clear the code and check whether it comes back
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.