[ltujustas]

Hi all. I have some problem with mrs unit on e46, there is temic 65.77-8372521 . Airbag have crash data "Internal control unit error", somedays ago I have restored airbag unit, but after few days drive crashdata comes again. Why crashdata writes again in ecu ? Maybe inside ecu something broken and need new ecu ?

[Vojno]

I have no concrete information, but enter this error directly because this event occurred.
Testing or simple deletion should not be used again by the SRS system.
I've seen this error several times, and the replacement is a reassuring solution.
I note quietly, there was maybe a call back action...

[ltujustas]

I have found problem. It's not ecu fault. small voltage drop will write crashdata in memory on these airbag ecu's, have tested with dead battery.

[Enabled]

Interesting, good job.

Internal error is not necessarily crash data.

[Vojno]

As far as I know, the MRS runs a self-test and if something is wrong, it disables itself! (internal error and locked)
This is possible for many reasons:
- excessive collision event, many airbag launches
- internal failure, software or hardware failure during self-test,
- and perhaps if "crash data" exist then locked to be evaluated
They cannot be deleted by simple diagnostics!

without being exhaustive

[PhilipM]

Can also be bad coding, eg if you have coded out a seat occupancy sensor, but the sensor is still connected, it can decide that the coding and memory must be faulty.