Hello fellow MX5 owners!
I have a 1994 1.8iS and the air bag light is flashing “code 52”, which apparently means “Damaged back-up battery”. From lots of googling, it seems that the back-up battery is in fact a capacitor on the airbag module located under the dash.
I rang a few Mazda specialist and they said the module would need replacing, which involves taking out the whole dash. But, I have a feeling that this is only for cars with the passenger airbag. My car doesn’t have a passenger airbag and I can see the blue diagnostics box under the driver’s side dash, but they don’t have a module to replace it with. I rang a few companies which specialise in airbag module repair and none of them said they could repair or replace the module. Is there any chance that anyone on here has or knows someone who can replace or repair the faulty module?
Thank you for your help in advance!
Is the problem that the air bag module is not available from Mazda anymore or that the specialists that you spoke to don’t have one in stock? According to the workshop manual the dashboard has to come out to change the “module” but that’s not as a big a job as it sounds that maybe to gain access to remove the bracket mounting nuts. Obtaining the parts will be your biggest hurdle I reckon.
Be aware that the air bag system changed from December 1994 production from a “diagnostic module” with separate crash sensors to a standalone “SAS unit” so if you’re looking for used parts then be sure you are getting like for like.
Thanks for the quick reply Robbie! The problem is that the specialist I spoke to don’t have one in stock. I presume the stock they had previously was second hand since they said “we had one from a 1994 car but it’s been sold now”. I rang the local Mazda garage too who couldn’t tell me if they could get the part but can book me in for a “diagnostic check” at the cost of £50.
I completely agree that getting the part will be the biggest hurdle! Months of Google searches has bared no fruit!
Thanks Robbie, I’m pretty sure the one I have is a blue “diagnostic module” (the car was first registered in May 1994), but I will definitely double check in case I’ve been looking at the wrong this this whole time.
I was really hoping there’d be some sort of tech guru out there somewhere that I can send the module too, they work what I can only presume is magic and then I can drive with a little less fear!
I presume that this is the fault diagnosis module?
Yep, that looks like the early type, did you slide it off the bracket and leave the bracket in place?
I did, it that not the right way to take it off? 
Saves removing the dash 
Why can’t your Mazda dealer tell you if the part is available or not? There’s no point paying their £50 diagnostic charge if they can’t actually repair it!!! I’d ring them back and just ask for the price and availability of the module as an over the counter sale, clearly you’d be able to change it yourself.
When I removed it to get the parts numbers, I got a little bit worried that I got it out so easily after reading everywhere that it requires taking off the dash 
So I rang Mazda again and spoke to the parts department, they said the part is unavailable. So it seems that ringing them again has saved me £50 and a 30 mile round trip for them to tell me there’s bugger all they can do!
Good news though, it turns out that the same diagnostic module, with the same parts number, was fitted to the Ford Probe, and there’s someone on eBay, in Latvia, that has one for sale for £60! I think I’m gonna go ahead and order it, and hope for the best. Thanks for all your help Robbie, and I’ll keep you informed on how it goes!
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Have you ordered the part from Latvia?
A colleague is breaking an early MK1 1.8 with what appears to be the same system and it was working.
I have sent you a private message. Part(s) would be guaranteed.
To be honest not seen this type of airbag system before in the UK - thought it was a Miata thing. The ones I see are I guess the later ones with the Crash sensor that requires dash removal.
