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 antenna coil around the ignition switch or its connector
- The body control module (BCM) software: per GM bulletins some of these faults are fixed by a software update
- Low voltage: a flat battery or corroded terminals
What you can do yourself
- The security lamp is on or flashing; the car usually starts but may not recognize the key.
- Per GM bulletin 16-NA-128 (Trax, Tracker, Opel Mokka 2015–2016) the body unit wrongly sees an open in the antenna circuit: no parts are replaced, the unit’s software is updated.
- Dim dashboard — check the battery: with low voltage the immobilizer may not recognize the key.
- Try the spare key: if it starts with it — the problem is the first key; if it doesn't start — the antenna at the ignition switch or the car's control unit.
- The immobilizer is never disabled or bypassed: it is theft protection. The fault is found and fixed.
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 16-NA-128, PI1180A (static.nhtsa.gov)
On Oleg’s website:Car computer diagnostics ↗
The explanation comes from the error code reference in the AvtoElektrik PRO app.