SRS Hard fault

Hi Guys, can anyone tell me if it is possible to clear a hard fault from the SRS control module in an 04 L322 without removing it from the vehicle. I am fairly sure I came across someone who had done it. The disconnect unit on the battery caused the hard fault rather than an air bag deploying. Thank you in advance.

Not sure what you mean by hard fault, I’m only familiar with that on EAS.
If you have the SRS light on and BDU fault I have cleared that with allcomms.
What diagnostic do you have?

Just to make it clear @tango90 the BDU unit that @holidaychicken mentioned is "battery disconnect unit " its the yellow connector on battery positive clamp, I had a problem with mine which was just a bad connection bit of a spray with contact cleaner and fault then could be cleared.

^^^what he said, I've had bad connection also, on the bolt to the battery clamp. Cleared with a Foxwell and cleaning the terminal.

Yes the fault showing is "battery disconnect unit 1" but this has been changed and checked as working and the fault will clear but returns immediately. An auto electrician who drives a range rover and is familiar with them checked it for me and has diagnosed it as a hard fault in the ECU and needs to be removed and sent to be cleared, but I am fairly sure I came across mention on a forum that even crash data can be removed and the ECU reset without being removed from the vehicle. Maybe wishful thinking but I hope not.

tango90 said:

Yes the fault showing is "battery disconnect unit 1" but this has been changed and checked as working and the fault will clear but returns immediately. An auto electrician who drives a range rover and is familiar with them checked it for me and has diagnosed it as a hard fault in the ECU and needs to be removed and sent to be cleared, but I am fairly sure I came across mention on a forum that even crash data can be removed and the ECU reset without being removed from the vehicle. Maybe wishful thinking but I hope not.

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I doubt crash data can be removed or the crash sensors reset, but I would have thought any other fault code could be cleared with the ECU in situe.

It can be cleared but with a dedicated software, sometimes dealer only.
I've a client with a Mercedes A180 that had a bump and now the passenger airbag/window airbag module has a listed fault. He needs to get it cleared via the dealer. Has the car had a bump previously?
The charge on the battery pops to protect the vehicle from driving in the case of an accident.

I had the same that wouldn't clear as in the airbag red light was on and fault code present, from memory i had ignition off and disconnected the yellow connector, ignition on.
Ignition off and reconnected then ignition on and red light still on and fault present but then when I cleared the fault with allcomms the red light would flash on and off for about a minute and then stayed off and been fine since. i may have cleared several times with allcomms until it finally cleared and the red airbag light stayed off.
i don't know if the disconnect and reconnect did anything but it made me feel better by contributing.
I think if the vehicle has been in a crash and airbags deployed and BDU activated you could get a hard fault as you describe but i don't think you would get only the BDU code on it's own.

There is a specific method of disconnecting and reconnecting the BDU, if that has not been followed then that maybe how the fault has been created. Instructions how to do it are in RAVE.