Friends,
The above light has started to flash say every 10 seconds on my 2010 MX5.
It lights up when the ignition is on then goes out and then flashes a couple of times every 10 seconds.
There is no audiable beeping
Anyone have any ideas what could be causing this.
Cheers
Mv
Probably a bad connection at the connectors under the seats. Try sliding them back and forwards a few times, that may be enough to make the connection good. Failing that you’ll need to get the fault code read.
Robbie,
Many thanks, the seat is moved back and forth quite alot as I am taller than the other half.
The light flashes 4 times and then a 2 second pause and then 2 times and then abut a 6 second pause and then cycles again.
I had a glance under the seat, there appears to be a large connector that is about the size of around 2 boxes of matches. It is on a hanger but for the life of me I cannot seem to break it apart. It is white in colour and seems to have some sort of locking bar or similar.
Help would be appreciated
Cheers
Fault code 42 is the primary crash sensor.This is at the front of the car,possibly by the bonnet catch or down on the front chassis leg.Try disconnecting and re-connecting,but disconnect battery first.
Many thanks, any chance you have a photo of the sensor???
I’ve had the exact same issue crop up on mine this morning! I have an '06, but I get 3 short flashes and 2 long ones of the airbag light on the dials. It happened after I reversed into a car parked behind me as I was trying to get out of a space. It was a bump, but not anything to cause damage or scuffs. I stalled the car because of it, and it came on after I restarted the car. It was flashing the whole way to work. I tried clearing the fault with Dashcommand app, but that didn’t seem to work. Is there another crash sensor in the rear bumper?
Roadster robbie was right in my case. I took it to my local mechanic and he cleared a number of faults related to the passenger seat. Nothing related to a rear crash sensor like I had previously suspected given the circumstances for the fault to start in the first place. It was low seat pressure sensor signal and low passenger airbag sensor signal. The connection under the seat had jiggled loose. He cleaned off the terminals and reseated the connectors. fault is gone and has stayed off.
Gents,
My local garage have confirmed the codes relate to the main crash sensor.
The codes are B104D and B2856.
The garage (and also Mazda) are unsure as to whether this can be:-
alternatively
The garage (and also Mazda) believe that the sensor probably will not require the ‘matching’ in item 2,
They believe the sensor is down below the bonnet catch and will require bumper removal
I would appreciate someones thoughts on this.
Cheers
Paul
I’ll post some firm details on this when I’m back from the NEC Classic Motorshow this weekend. Drop me a PM to remind me after the weekend.
You’ve described the light as the airbag seatbelt pretensioner warning light. For the avoidance of doubt, can you confirm that the light you are referring to is the airbag (or SRS) warning light.
Both of the codes refer to a fault with the crash zone sensor which is installed behind the front bumper, with the bumper off you have to remove the fresh air duct which leads to the air cleaner to gain access to the sensor. It’s behind a metal cover. It could be a tricky one to diagnose, the cause of the fault could be a faulty crash zone sensor, faulty wiring between the sensor and the SAS unit (air bag control module) or a faulty SAS unit. The SAS unit is located on the transmission tunnel just in front of the gear lever.
The diagnostic procedure is not simple. All you can do is visually inspect the sensor itself and its connections, check the wiring harness for open circuit, short circuit, short to power or short to ground and if all that seems OK, replace the SAS unit. Checking the wiring harness should not be carried out with any air bag component connected as using an ohm meter on the harness may set off an air bag. My advice is leave it to a professional to check.
There is no way to test the operation of the crash zone sensor so it is impossible to know if it has an internal fault. The diagnostic procedure says that once satisfied that the wiring is OK and the sensor is visually OK, replace the crash zone sensor then try and clear the fault codes, if they remain, the next step is to replace the SAS unit. The sensor is a simple plug and play unit and could be swapped from another car to confirm if it clears the fault, the SAS unit is a programmable module and needs to be configured using Mazda’s diagnostic equipment. Information is copied from the original unit and written to the new one.
Hope that answers all of your questions.
Dear Robbie,
Thanks for your time in writing a very comprehensive response.
The warning light is described in the page 5-45 of the Mazda handbook as ‘Air Bag/Seat Belt Pretensioner System Warning Light’
My local garage is not a Mazda dealer but they are confident that it is the crash sensor itself and are confident that it is not the wiring. Saying that, they did not remove the bumper and do a visual inspection of the main crash sensor. Perhaps they have confidence in the build quality of Mazdas (or some other reason) to ascertain there is no wiring problem at the sensor. They are a very established garage but I do understand they don’t have the full kit and perhaps expertise that Mazda have.
I assume if it goes in to a Mazda dealer they will have to remove the bumper and inspect the main crash sensor. My local garage will be cheaper than a main dealer. If a bumper removal and replacement of the sensor is required then I’ll definately at least get that done with my local dealer.
Cheers
MV
Friends,
Thanks for all your help on this. It turned out to be the main crash sensor. This was replaced by a local garage which included removing the bumper and fitting a new main crash sensor and clearing the code from the ECU.
My wifes lovely car is back to normal so thanks for all your assistance
Hi. I have a fault light , flashing airbag light. Just flashes twice, every few seconds. I will try the obvious fixes first (battery disconnect and whip the seat(s) out and spray the connectors with electrical contact cleamer)
it would help to know what the code refers to, tomsave me whipping out both seats!
There is a list of air bag flash codes for NA & NB in the technical Downloads area.
many thanks, however mine is a NC (sorry I should have said that)
I’m hoping the codes are different to the NB otherwise I need another SAS unit