SRS ECU replacement

Hi all, thank you for all the helpful threads - this site's a goldmine of information.

I have a 2001 v6 Freelander 1. The SRS warning light comes on sometimes (other times it goes out after a few seconds and stays off).

I have soldered the underseat connectors following advice here, but that hasn't solved the problem so I took it to an LR garage for diagnostics. They say the SRS ECU is shot and quote £195 plus £25 programming for a replacement (with the caveat that this may uncover other faults - which is to be expected). I may go down this route but see that second hand ones are much cheaper than this on eBay. Would they need re-programming, though? I've also seen websites which reset airbag ECUs for £60. Does anyone have any experience of using these?

It seems strange to have an intermittent fault as a result of a fried ECU. I would expect to find a dodgy connector or faulty earth somewhere, but I've plugged and unplugged the driver's airbag and rotary coupler connections (the underseat wires are soldered, as mentioned above). I guess it could still be the passenger airbag or connection to the ECU?

Thank you for any help you can offer me.

Can anyone help with this one? I doubt I'm alone in suffering SRS ECU problems. Or do people generally just pay Land Rover for a new unit?

Saying the ecu is shot is one thing,but what faults were logged in it ? Did it log internal failure ? Many garages are wary of testing or dont know how to check out SRS looms etc.
Where are you,maybe someone on here could help you...
BTW, a s/hand ecu can plug straight in.

Thanks - that's really helpful. First thing I'll try is another ECU. The garage report simply stated that the ECU had an "internal fault". I suppose that a loose connection to it could generate this sort of failure report on the testbook used by the garage?

By way of update: I've taken the fascia out and removed the heater unit to access the SRS ECU. It seems that the ECU takes its earth locally rather than through the loom, but the contact looks a little tarnished. Could it be possible that a poor earth here could be causing the intermittent SRS warning light? It might also explain why the LR guys thought there was an internal fault in the module - it didn't have a good earth.

Anyway, I'll be putting the ECU back with hex bolts rather than torx and have cut the carpet so that I'll be able to replace it next time without taking out the heater unit. What a daft piece of design. I'll try cleaning up the contact first with a file and protect it with some silicon gel. If that doesn't work, I'll try a replacement second hand unit from eBay (guaranteed to be working apparently - we'll see) and then a new unit from LR if no joy. There's no sign that the heater matrix has been leaking - just that the earth was assembled dry and the car is a decade old.

Airbag warning light's gone, so I'm guessing bad earth was the answer. Either that, or cleaning up and reconnecting the ECU and passenger airbag connectors. (I tried the driver's airbag and rotary unit before anything else and the seatbelt pre-tensioners were soldered - see above). Moral of the story, worth trying this before investing in a new ECU!

Thanks for telling us the result.

evening all,im trying to find some info on the airbag ecu i have a warning light permanentky on ,i need to replace the ecu , can anyone tell me if its possible to replace just by removing the carpets rather than having to take all the heater matrix out , thanks.

must be srs time
my light been on for over a week now I ve tried all the connecters under the seats and the steering rotary thingy
like you say you can get guaranteed fault free ecu units of ebay but surely if there is a fault and its not cleared and you plug the new ecu unit in will it not pick the fault up and you be back to square 1 im not sure how it works to be honest maybe someone could enlighten me somemore landrover want £100 to clear the fault light and that's without finding the fault
oh and I read a thread somewhere about cutting a hole in the floor carpet to make it easier to get to the ecu

The airbag module should be replaced at 10 years regardless of mileage according to the service schedule. Maybe that's the problem?

sijwhite said:

The airbag module should be replaced at 10 years regardless of mileage according to the service schedule. Maybe that's the problem?

Click to expand...

I've never known any one to do this....... Ever on any car... The only time they get replaced generally is if they go off.

And as far as I am aware airbags and ECUs don't know today's date so they don't know how old they are...:bolt:

ZDomZ said:

I've never known any one to do this....... Ever on any car... The only time they get replaced generally is if they go off.

And as far as I am aware airbags and ECUs don't know today's date so they don't know how old they are...:bolt:

Click to expand...

All airbags are marked with a replacement date, side airbags on the P38 have a 10 year life, fronts have a 15 year life. The ECU does not flag the need for replacement and I've never known anyone replace them. I've removed the side airbags on mine and do not intend to replace them as they are useless in an accident.

Recovered a car the other month on the police contract with side air bags (in the seats) the airbags had deployed but were prevented from doing so properly because the owner had fitted seat covers that were not sips compatible. I don't know if they would have saved her life in the impact but they might have given her more of a chance.

ZDomZ said:

Recovered a car the other month on the police contract with side air bags (in the seats) the airbags had deployed but were prevented from doing so properly because the owner had fitted seat covers that were not sips compatible. I don't know if they would have saved her life in the impact but they might have given her more of a chance.

Click to expand...

The one that deployed on my P38 went out into the rear compartment so would have done nothing to protect me had it been needed. All I did was slid into a ditch on an icy lane, too bloody sensitive IMO.

I was talking about a Saab 95 sideways into a communications pole........ It weren't pretty.

ZDomZ said:

I was talking about a Saab 95 sideways into a communications pole........ It weren't pretty.

Click to expand...

Ouch

adamgamsa said:

Airbag warning light's gone, so I'm guessing bad earth was the answer. Either that, or cleaning up and reconnecting the ECU and passenger airbag connectors. (I tried the driver's airbag and rotary unit before anything else and the seatbelt pre-tensioners were soldered - see above). Moral of the story, worth trying this before investing in a new ECU!

Click to expand...

_____________________________

Hi, sorry to revive an old thread but I've got this problem now... PITA! Scanned it for codes and it listed the airbag ECU and fault as well as "low battery voltage" and "srs warning lamp circuit fault". Then after this I renewed the rotary coupler and airbag with a known good one, same result, SRS light stays on permanently. I renewed the Airbag ECU and still same result. The connection didn't really appear dodgy though, I did away with the torx bolts and used normal bolts. Interestingly however, in really really hot weather when the cars been sitting outside, when I turn on the car the light will come on and extinguish after 5 second (as it should normally). Otherwise other times I turned it on it will stay on forever... I have an icarsoft scan tool and try and erase the codes but they return immediately afterwards.

Hi, I also meant to say that I replaced the airbag ECU with a second hand unit from some Rover breakers who said it was a known good one.

Check the under seat connections and all other connections. It might be worth pulling the SRS fuse to check for corrosion on the blades.

Have you checked the wires going to the pretensioner on the seat belt - they can become dislodged. Might be intermittent.