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 engine ground is loose or corroded
- The wiring harness has chafed on the alternator bracket or an A/C line
- Low voltage: a flat battery or corroded terminals
- CAN bus connector or wire
What you can do yourself
- Check the battery and terminals: at low voltage control units lose communication.
- Check the engine ground: the ground strap is tight on the engine and on the body, with no corrosion. Per a GM bulletin, a loose ground sets many communication codes at once.
- Inspect the wiring harness by and under the alternator: per a GM bulletin it chafes on the alternator bracket.
- Look at the codes of the other units: if communication is lost with several units at once, look for a common cause (ground, power, bus wire) rather than replacing units.
- If the code is only in history and the car runs normally, clear it and see whether it comes back. If it doesn’t, no repair is needed.
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.
This is the GM meaning (Chevrolet, Cadillac, GMC). On other makes this number means something else: if your car isn’t made by GM, change the make at the top.
Source: GM 23-NA-102 (static.nhtsa.gov)
The explanation comes from the error code reference in the AvtoElektrik PRO app.