I owned a freelander 1 2006 TD4 and was involved in an accident where the front passenger side got damaged including the fender, bonnet, radiator support and shock. The vehicle has since been repaired but now the SRS light is permanently being displayed on the dashboard. I have had a diagnostic test tool attached but have been unable to reset the SRS light and there are not fault codes found. However, the following was shown on the diagnostic tool:
1) Belt pre-tensioner left fault: resistance too high sporadic and is causing MIL on
2) Internal Fault: Replace SDM
3) Battery too high

In spite of the above message no MIL is being displayed on the dashboard; just the SRS light.
I understand that when the ignition is switched on the airbag DCU performs a bulk check of the SRS warning lamp. If the data received indicates vehicle deceleration at or above a preset limit, the airbag DCU interprets this as a collision and performs deployment of air bag and retraction of the seat belt pre-tensioners. Then DCU enters crash locked mode and illuminates the SRS warning light. However, the airbags were not deployed and would imply that the DCU did not act probably because the collision was not severe enough.
Please can anyone assist by letting me know:
1) How to get rid of the SRS light?
2) What exactly is the SDM mentioned in the message?
3) As the airbag was not deployed does that mean that the DCU did not enter crash mode and therefore is still in working condition?

I have attached below the information of the operations of the airbag DCU and it's associated impact on the SRS light.

Once the srs light has come on it needs the ecu replacing (there's a a separate one for the airbag system), mine popped up a few weeks ago and it just stays on now (I didnt have an accident, haven't checked the codes yet), can get a new ecu on fleabay for 10-30£

Sounds like the DCU and left belt tensioner need replacement. The air bags don't always deploy in a crash, but pre-tensioners might.

Thanks Nodge68 & Phoebecp.
Is the ECU and DCU the same thing? If so, is there a separate one for the pre-tensioner compared to the airbag?
I'm guessing that by Fleabay you mean ebay?

did you have it repaired at a reputable garage if so take it back they give you a guarantee these days

The vehicle is in the Caribbean and is a challenge for most garages there.

oh dear

zimaria said:

Thanks Nodge68 & Phoebecp.
Is the ECU and DCU the same thing? If so, is there a separate one for the pre-tensioner compared to the airbag?
I'm guessing that by Fleabay you mean ebay?

Click to expand...

Yes. Same thing. The belt pre-tensioners use the same DCU to trigger them. They are triggered under a different set of parameters, compared to the airbags. The DCU and triggered pre-tensioner need to be replaced. You can tell if the pre-tensioner has bee triggered, just by looking at it.

Thanks Nodge68.
It is a SRS ecu or pretensioner ecu replacement that is needed?

zimaria said:

Thanks Nodge68.
It is a SRS ecu or pretensioner ecu replacement that is needed?

Click to expand...

The airbags and pre-tensioners are both controlled by the DCU. The 2 systems just detonated under a different set of parameters, under the control of 1 control unit (DCU).

Thank you very much, Nodge.
Armed with your info. I've identified the part needed as the AIR BAG ECU CONTROL MODULE.
However, I'm being given 2 different part numbers and not sure which is correct: YWJ000131 and YWC000610.
Any idea?

zimaria said:

Thank you very much, Nodge.
Armed with your info. I've identified the part needed as the AIR BAG ECU CONTROL MODULE.
However, I'm being given 2 different part numbers and not sure which is correct: YWJ000131 and YWC000610.
Any idea?

Click to expand...

Which PN would depend on year and spec. The easiest way to check that, would be call an LR dealers. Ask for the DCE price, then ask for the PN "for future reference"