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
- Several start attempts with an unprogrammed or faulty key (usually 5+)
- Faulty key (most often the transponder in the key)
- Faulty NATS antenna amplifier at the ignition switch
- BCM/IMMU, ECM or NATS system wiring problems
What you can do yourself
- Take a working programmed key, turn it to ON for 5 s, then OFF — repeat 3 times and try to start
- Inspect the key for cracks and wear
- If the security light does not come on when starting — the cause may not be NATS
- If that doesn't help — see an auto electrician/dealer for diagnostics
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.
Source: obdadvisor.com
The explanation comes from the error code reference in the AvtoElektrik PRO app.