04 Freelander SRS light - SOLVED

[guineafowl21]

As above, I’ve checked the yellow connectors under the seats, and by back-probing them have ohmed the pre-tensioner coils - both 2.33 ohm.

Replaced the rotary coupler, and ohmed the driver’s airbag module, again, 2.33 ohm.

My version of RAVE doesn’t seem to cover the facelift Freelander. It says the airbag control module (DCU) is on the transmission tunnel behind the centre console, but I can’t see it. It’s my next port of call, as from its main connector I can check the integrity if the wiring to all the parts.

Does anyone have any more suggestions (I’m trying to find someone with a code scanner for airbags), or know where the DCU is on the facelift?

Cheers.

 

[Nodge68]

It's not generally wise to resistance test air bag modules, because of the chance of detonation. I'm guessing you're DMM has a very low test current, or you'd have found out by now.
Have you checked the passenger air bag?. Ideally you need to prove the wiring as well as the control module. As far as I know, the module is mounted behind the heater unit, bolted to the bulkhead.

 

[guineafowl21]

It's not generally wise to resistance test air bag modules, because of the chance of detonation. I'm guessing you're DMM has a very low test current, or you'd have found out by now.
Have you checked the passenger air bag?. Ideally you need to prove the wiring as well as the control module. As far as I know, the module is mounted behind the heater unit, bolted to the bulkhead.

Yes, but (famous last words) I saw a Youtube video where they ohmed an airbag

More seriously, I checked the OCV of the meter (2.5V) and the short-circuit test current (1mA and below). It is a half-decent Fluke 87V so I hoped it would be fine. The diode function (<= 7.2V) is a different story. For anyone reading this thread, as Nodge says, if you’re not sure, don’t try it.

Also confusing are the metal clips that bridge the contacts of the connectors while unplugged. You have to back-probe the assembled connector.

Just back from the garage nearby - they charged £10 and all that was needed was to clear the codes, which were high resistance on both pre-tensioners. I guess one connector got loose, I solved that, and then the other code was set by my fiddling. Very annoying that the codes don’t self-clear.

Cheers Nodge.

 

[Alibro]

It's not generally wise to resistance test air bag modules, because of the chance of detonation. I'm guessing you're DMM has a very low test current, or you'd have found out by now.
Have you checked the passenger air bag?. Ideally you need to prove the wiring as well as the control module. As far as I know, the module is mounted behind the heater unit, bolted to the bulkhead.

Funny I was thinking the same thing myself Nodge. I wouldn't be brave enough to put a tester near an airbag.

 

[Nodge68]

Funny I was thinking the same thing myself Nodge. I wouldn't be brave enough to put a tester near an airbag.

It can be done, but you need to know your test equipment.
A decent DMM will have a very low test voltage and current. However not all are low enough to test air bags safely. Older meters, particularly analogue meters can triggers air bags. Air bag igniters need anything from 100 mA up to a few Amps, depending on the manufacturer.
I'm not generally brave enough to try measuring them myself. I just use a diagnostic device instead.