Airbag ecu/neutral terminal

[Sue26]

Hi. Not yet a member but in need of urgent help.
The airbag light has come on after being in storage for 6 months and i have been advised to send it off to crash data liverpool. I leave loosened the bolts on the ecu but not yet disconnected it and I believe I need to remove the neutral connection to the battery before disconnecting the ecu. Problem is, there are two chunky black leads and I don't know which one I need to remove(or both?). Mot expires Wednesday so I really need to get this sent off today. Just to add to my woes, I've taken a picture of the terminals but I can't see how to upload it to my post.
Hope this all makes sense.

Sue
Can anyone help please?

 

[donkey]

Disconnect all cables from Negative battery post.

Do you have solar charging, if so you may still have voltage at ECU, even with battery disconnected.

Geoff

 

[tonyidle]

Remove all connections on the - ve starter battery post.

And as mentioned by donkey best disconnect solar too.

 

[Gellyneck]

I disconnect both +ve and -ve terminals to be sure.

 

[Sue26]

Thank you for you responses.
I've managed to disconnect everything from the negative terminal and remove the ecu.
It's currently in the post to crash data and can hopefully be repaired.
I will update you with the outcome when I have it back. In the meantime, i will get my subs paid as I suspect I will be back with other questions going forward.

Thank you again.

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[donkey]

Hi
I suspect your problem was related to low battery volts due to a discharged battery.
While the ECU is away you need to make sure the vehicle battery is fully charged before reconnecting and trying to start the vehicle.
So, take the time to charge the vehicle battery, probably easiest to use a stand alone battery charger connected to the battery, but without reconnecting the negative cables.

If you are not sure, then get back on and we will guide you.

Geoff

 

[Sue26]

Hi Geoff.
I believe I may need to invest in one of those ctec things as we usually charge the batteries while on hook up.
For now the only other means we have of charging the battery without the negative connected is by a portable suitcase solar panel clipped direct to the battery and hope for some sunshine.
We did have the van on hook up over the weekend so hopefully we have put some life back into the battery. I will check it with a meter while the ecu is away and connect the solar if the voltage drops. Hopefully we will get the ecu back weds/Thurs and we will have a good outcome.
Thank you for your assistance.

 

[donkey]

Hi

It appears you have a good understanding of system. So, it would be ok to reconnect the cables to the battery and leave it in EHU charge until the ECU is returned. No need for a separate charger if you make sure to disconnect battery before replacing the ECU.

Geoff

 

[Sue26]

Hi Geoff
It's funny how fast we learn when we need to! I didn't know what an ecu was until last Friday and it was only Google searches and comments from members on here and other forums that got me to where I a now. We've had the van for just over four years and fortunately this has been our biggest problem to date.
Hopefully crash data will get the unit repaired and back to us weds/Thurs then we've just got to get the mot sorted.
Thank you
Sue

 

[Sue26]

Quick update.
Posted ecu to crash data Monday, received back Wednesday, MOT test and passed Thursday! Good result!
Diagnostic report from crash data recorded high voltage @ 14.7v. I'm a bit puzzled by this as moho had been in storage with no hook up for approximately 5 months
Thanks to all for advice.

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[jezport]

Quick update.
Posted ecu to crash data Monday, received back Wednesday, MOT test and passed Thursday! Good result!
Diagnostic report from crash data recorded high voltage @ 14.7v. I'm a bit puzzled by this as moho had been in storage with no hook up for approximately 5 months
Thanks to all for advice.

Heard that before from reports people quote. But 14.7v isn't a particularly high voltage. AGM batteries charge at 14.7v

 

[Sue26]

Ours is a standard lead acid starter battery.
I guess I will have to keep an eye on it. Hopefully all will be well as we start to use the moho again in the near future.

 

[Lofty1]

If your battery is low when you start the engine,if you rev it ,it can create a surge from the alternator often above the 14v mark, answer is to charge after being stood or not to rev up when starting

 

[Riverbankannie]

Mine was quoted as too high at 14.6. ECU too sensitive in our opinion. Too many of these happening.

 

[Sue26]

Thanks for that information lofty1. I will have revved it when I first started it after it being stood for a few months so I may not have helped the situation.
Hopefully we won't have the same problem next winter if the moho isn't stood idle for quite so long

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[autorouter]

I don't know about airbag controllers specifically, but in general any automotive electronics must be capable of withstanding the harsh voltage conditions often found in a vehicle. There are many relevant standards, and manufacturers often have their own proprietary standards too. But basically anything electrical in a vehicle must not have a problem with 10 to 35V. Some devices (radio etc) can just shut down until the voltage returns to normal, others (brakes, engine etc) must work properly whatever voltage is thrown at it. I sincerely hope that airbag ecus come into the latter category. An error at 14.6V means it's not fit for purpose.

 

[Sue26]

'Not for purpose' probably right I'd say judging by the number of reports about airbag ecu errors if read since having one myself.