Lost communication with airbag control module
Where to start
No communication with the airbag unit. ⚠️ This is where do-it-yourself is out of place: a wrong write into the airbag unit costs an airbag that does not fire in a crash, or one that fires without one. Checking a fuse is fine; everything else belongs at a garage.
«No communication» is about the bus, not the unit
⛔ «No communication» almost never means «the unit is broken». It means one unit stopped hearing another, and the usual causes are power, ground and the bus — not the unit itself. Replacing a control unit on this code is the most expensive mistake in the whole reference.
Read the number of them. Several «no communication» codes at once point to something shared: power, ground, or a break in the bus. One code alone points to that unit's own connector and its power. Five missing units almost never mean five broken units.
⚠️ These codes also appear on their own after the battery has been disconnected, and clear themselves after a few trips. Clearing them without finding the cause is fine only in that case — otherwise they come back before you leave the yard.
How to put together a report a mechanic will actually read
How the code is built
All codes in «Communication between modules»
How the app helps
CarScan reads this code from your car through an OBD-II adapter, shows whether it is active now or only stored, names the module that reported it, and puts it into a plain-text report for your mechanic.