75ZT Community

Who the hell decided to put the SRS (Supplementary Restraint System) ecu under the centre console? Had the airbag light come on on my way down to East Kirby and the usual wiggle of the wires under the seat did not clear it. so, when we returned home removed both seats cleaned and re-seated all connections and turned ign on. still no better. Booked an appointment with my good friend BigRuss and his T4 (Testbook version 4.Computer Diagnostic System).

The T4 will not talk to the SRS unit and fuse 18 is intact. As Russ has previously experienced it is usually the case that the SRS unit has failed. YWC 106970 is the correct one for my launch car.
So asked Russ where it is situated and he started laughing (never a good sign with Russ). He pointed to just in front of the handbrake. Stupid place. anyway its out and the elastoplast box is well used, just finding a replacement now.

Oh and whilst i'm on why use stupid type bolts that sends you scrambling through your socket set to see if you have the right type fitting. Grrr

Dave let me just run down to the shed and see what i have, i know i have a few of those, but will one be for your car.

Ok so yes I have three two which are the same (YWC107090)

One which is (YWC001160)

But not one with (YWC106970)
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I'm sure the one (YWC001160) came from a 2.5 petrol engine but it has 2003 on the rear of it.
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Are they not interchangeable

Hi Steve, not sure if they are interchangeable, physically the two you have that are the same are the same as mine but just a different part number? i think I have one coming now that is the same part number so see how that goes, thanks for looking, if it turns out the one coming doesn't work or they are interchangeable I will be back in touch.

There seem to be two distinct versions. The older one has a yellow connector, the newer orange. Not sure how the part numbers vary. I've also seen one that just died, but a replacement unit fixed it.

Regarding the location. The module isn't just a controller, it actually has an acceleration sensor inside, and as far as I'm aware a 'safing' sensor. The accelerator sensor is how the unit decides you have had a crash, and the safing sensor is a physical double check so if the computer has a bad day, it can't accidentally set off the bags. Those were for sure a feature of earlier systems, but can't 100% say whether our cars still have them. The point being, the unit needs to be central in the car for those sensors to work. They are there, or thereabouts in all cars.

One thing I've come across. On an earlier car where a unit failed, the owner obtained a replacement from another car. Same part number. Fitted it but the airbag light stayed on. I put it on the T4 and before I even got to query it, the T4 said there was a coding (ZCS) mismatch and recoded the airbag ECU (Engine Control Unit). Airbag light was off. Stored codes pointed to rear pretensioners. Can't remember which way round but donor car was a tourer (no pretensions) and reciever was a saloon (with pretensioners). Airbag ECU didn't like that, but when T4 recoded it, it was happy.

EDIT: oh and the stupid bolts are to make sure the correct tools are used to fit and remove with correct torques. The tightening torque is recorded with the build history at the factory. That said, i've never had a problem using a standard socket on them. After all it's a safety system.

EDIT again: It was Probably Steve Viner.

Duncan wrote:There seem to be two distinct versions. The older one has a yellow connector, the newer orange. Not sure how the part numbers vary. I've also seen one that just died, but a replacement unit fixed it.

Regarding the location. The module isn't just a controller, it actually has an acceleration sensor inside, and as far as I'm aware a 'safing' sensor. The accelerator sensor is how the unit decides you have had a crash, and the safing sensor is a physical double check so if the computer has a bad day, it can't accidentally set off the bags. Those were for sure a feature of earlier systems, but can't 100% say whether our cars still have them. The point being, the unit needs to be central in the car for those sensors to work. They are there, or thereabouts in all cars.

One thing I've come across. On an earlier car where a unit failed, the owner obtained a replacement from another car. Same part number. Fitted it but the airbag light stayed on. I put it on the T4 and before I even got to query it, the T4 said there was a coding (ZCS) mismatch and recoded the airbag ECU. Airbag light was off. Stored codes pointed to rear pretensioners. Can't remember which way round but donor car was a tourer (no pretensions) and reciever was a saloon (with pretensioners). Airbag ECU didn't like that, but when T4 recoded it, it was happy.

EDIT: oh and the stupid bolts are to make sure the correct tools are used to fit and remove with correct torques. The tightening torque is recorded with the build history at the factory. That said, i've never had a problem using a standard socket on them. After all it's a safety system.

EDIT again: It was Probably Steve Viner.

Duncan
yes newer ones are orange, older one yellow.
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Dave let me know and it's yours