SRS light and major frustration

[Rossco196x]

Please will someone advise me some credible advice, i have an MX5 Mk 3 2009 that has the following fault codes relating to the SRS system. The car had signs of a front end bump and hence i think the guy that bought the car off the insurance company got "Mickey Mouse" to MOT it before it got sold on and finally ended up on my drive way.

Hi i have read the following fault codes detailed below relating to the RCM (air bag module) SRS system.

Any idea where to start. Some one had covered the SRS light with tape.

When i took the car to bits to investigate it looks like someone has bought a 2nd hand air bag kit off fleabay and fitted it including a replacement SRS module that has the following markings. N123 S in the box and W2T80371 as the part number.

I've had various "experts" saying i need to have the main cars ECU file deleted as the codes won't erase for £80 and others stating there is a fault still. The seat belt pre tensioners are fine and the car doesn't have side airbags hence where can i get some credible advice from on how to fix the faults so i can get an MOT.

1. Is the SRS module storing these fault codes and is it not working because the SRS is coded to the chassis VIN number and can't be simply switched from 1 car to another as i think this came with the flea bay kit.

2. Does the main cars ECU need to be re / reflashed to delete these codes. i've been told the ECU is has nothing to do with the SRS system .

Please don't reply unless you actually have an in depth knowledge of SRS systems as advise like disconnect the battery etc doesn't work.

Codes as follows,

On Demand Self-Test has been started
(WARN) [14:24:01.451] Test completed, found DTCs: B1047, B1055, B1058, B1059
DTC B1047

Code: B1047 - Side Airbag Cross Link To Another Firing Loop, Front Driver Side

Module: Restraint Control Module===END DTC B1047===

DTC B1055

Code: B1055 - Side Airbag Cross Link To Another Firing Loop, Front Passenger Side

Module: Restraint Control Module===END DTC B1055===

DTC B1058

Code: B1058 - Airbag Cross Link To Another Firing Loop - Loop No. 2, Front Driver Side

Module: Restraint Control Module===END DTC B1058===

DTC B1059

Code: B1059 - Airbag Cross Link To Another Firing Loop - Loop No. 2, Front Passenger Side

Module: Restraint Control Module===END DTC B1059===

I'm more than happy to pay to get the car fixed, i'm in the south in Gosport, PO12 2DR

[GreenV8S]

Rossco196x said:

Please don't reply unless you actually have an in depth knowledge of SRS systems as advise like disconnect the battery etc doesn't work.

I don't have the detailed knowledge you're asking for so take this with a pinch of salt, but it seems to me that those fault codes show the SRS controller is testing for and detecting a wiring fault i.e. that this is not just a stored fault code but a prevailing wiring fault.

[Fore Left]

I don't have the detailed knowledge you're asking for either but are any of these 'experts' a Mazda main dealer? If not, that's where I'd be taking it for diagnosis.

[E-bmw]

I don't have it either but would be doing the above, the only people who will have that level of expertise.

[Rossco196x]

Thanks guys, Mazda main dealers wont have anything to do with repairing the car as its recorded on the Hpi register, there take is buy a new car. I can get a replacement module from Mazda for £363 but there is no guarantee this will fix the problem.

A couple of experts have said an exisiting wiring fault , i have inspected the drivers air bag and the wiring looks OK but i don't trust who ever took out the dash and SRS module hence i have now found a knowledgeable Sparky who said he will have a look at the SRS module as theses are apparently coded from the instrument cluster.

Update to follow

[GreenV8S]

Rossco196x said:

Mazda main dealers wont have anything to do with repairing the car as its recorded on the Hpi register

Is it recorded as a write-off? What category? I would not expect a dealer to turn away work unless it was classified as not repairable.

[Rossco196x]

its either a cat c or d but back on the road. Just starting to get to the bottom of whats wrong with the car and it still points towards a fault in the seat side airbag wiring apparently

[poppopbangbang]

I'd say they had fitted a none fired SRS unit from a car with side/seat airbags. The firing loops are usually laid out differently depending on how many bags/what spec etc. hence recording errors on the firing loops.

[Richard-D]

Those codes in conjunction with a replacement SRS module would suggest the incorrect ECU has been fitted. I'd be looking to find a pinout of the ecu and testing to see if your car is wired the same way. The ECU will presumably be using differences in resistance to identify the different circuits. I'm surprised that there's a code built in for this fault.

If the firing circuits are cross connected due to differences in the pinout from the ECU you have 2 options:-

1] Amend the wiring in your car by swapping the pins in the plug. You'd need to be sure that that was the only difference though and would end up with a non standard car. Wait for loads of people's heads to explode now at that suggestion.

2] Fit the right ECU (obviously the preferred option).