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
- Open signal wire or open sensor ground
- Sensor connector or wiring: corrosion, an open circuit, a chafed wire
- The sensor itself
What you can do yourself
- The sensor usually sits under the battery or in the negative terminal together with the current sensor. Check its connector.
- The alternator may charge incorrectly.
- Check the voltage on the “Sensors” tab: 13.5–14.8 V with the engine running.
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.
The explanation comes from the error code reference in the AvtoElektrik PRO app.