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
- Key authentication failed when switching on the ignition/starting
- The key (transponder), immobilizer unit and engine control unit did not confirm each other in time
- Unprogrammed or faulty key, weak transponder signal
- Internal fault in the immobilizer or wiring
What you can do yourself
- Make sure you're using the original programmed key
- Move metal and extra tags away from the key, try the spare key
- Check the battery charge
- If it happens again — see an auto electrician/dealer for diagnostics
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.
Source: tat.net.au
On Oleg’s website:Car computer diagnostics ↗
The explanation comes from the error code reference in the AvtoElektrik PRO app.