Does anyone have direct experience of replacing the Body Computer (BC) on a Croma?
The BC is reputed to be part of the CODE security system, but I’ve been unable to get positive information on what is involved in changing the BC. If anyone has fitted a used BC, what coding or programming was needed? The BC certainly stores the radio CODE but this can be manually entered if need be.


Robert G8RPI.

g8rpi said:

Does anyone have direct experience of replacing the Body Computer (BC) on a Croma?
The BC is reputed to be part of the CODE security system, but I’ve been unable to get positive information on what is involved in changing the BC. If anyone has fitted a used BC, what coding or programming was needed? The BC certainly stores the radio CODE but this can be manually entered if need be.


Robert G8RPI.

Click to expand...

body computer is coded, you need to get code from old body and transfer it to new one or else key code light will be on and car wont start, or change whole set with key engine ecu...

flisko said:

body computer is coded, you need to get code from old body and transfer it to new one or else key code light will be on and car wont start, or change whole set with key engine ecu...

Click to expand...

Have you done this on a Croma? How did you transfer the the code?

Robert G8RPI.

Some firm data now.
Spare Body Computer arrived so I had a look inside. The bad news is that the CODE memory is in the microprocessor. This is a 164 pin surface mount device and while I have the correct equipment to replace this device the chance of getting the one from my car off and onto the "new" BC intact are not good so I've ruled that out. At least not for just a faulty fuel gauge. I did try the "new" BC in the car and confirmed that it gave a "Vehicle Protection Sytem" error with a dead car. Just Getting the BC out is a pain as it is held in with shear head security bolts so you have to drill them and use a stud extractor (M5).
So For a BC fault you either need a new one coded at the factory for your car, a set of BC, TEG, steering lock, ECU and keys (and ideally radio too) or the ability to swap a 164 pin surface mount IC without damaging it.

Robert G8RPI.

I've managed to repair my BC (see fuel guage thread), but have also located a company in the UK who say they can clone your existing BC to a used one you supply, They are j cracknell car sales or JCCARS. They are on ebay

www.ebay.co.uk/usr/jcracknellcarsales

and the web

https://www.jccars.co.uk/
I've not used them. They don't list the Croma BC but gave a quick positive response and quote when I asked them. Quoted cost was £75 plus postage. They do list the Punto BC which is very similar and uses the same microprocessor.

Obviously you can't use the car while they have the old ECU and can't even lock it. If you don't have secure storage you can get ready to finally unplug the BC, close all doors but drivers which should ideally be blocked open. Lock doors using remote, disconnect battery, remove BC tools etc, MAKE SURE YOU HAVE THE KEY out of the car then shut the drivers door. All doors will be locked and you will have to use the backup key in the door lock to get back in. Might be worth making sure this works before starting.

Robert G8RPI.


The Punto Body computer seems very similar so could have the same issue.