Swapping ECUs and BSI units

My C3 Delphi ECU, appears to have a faulty internal atmospheric sensor, and perhaps other things and I've been advised that the Delphi 9650043480 80929Q are notoriously difficult to get into to repair. So I now have access to a Lexia tool, and have purchased a kit consisting of Key Fob, BSI unit and Delphi ECU (same part numbers as original) from a breakers. Can anyone offer any advise as to whether I just swap the lot into the car, and redo the tests ? I've heard that this should work but my car mileage will change to the donor vehicle and the radio will stop working. So the question are:

1. is this totally reversible if I need to reinstall the original BSI and ECU? i.e. will the mileage go back to original and the radio work again?

2. Can I use the Lexia to reprogram the radio? or

3. Can I reprogram the replacement ECU, leaving the original BSI in place, to work in the car using the Lexia or will I need something else?

Any helpful comments are highly appreciated.

MistyCottage wrote:3. Can I reprogram the replacement ECU, leaving the original BSI in place, to work in the car using the Lexia or will I need something else?

You can not reprogram the ECU or BSI to match each other, you need a kit of matched parts (ECU, BSI and Key).

MistyCottage wrote:2. Can I use the Lexia to reprogram the radio? or

You will have much more luck with reprogramming the BSI to the radio than ECU to BSI. I don't have the info in front of me now, but that is the sort of thing you can do with lexia.

MistyCottage wrote:1. is this totally reversible if I need to reinstall the original BSI and ECU? i.e. will the mileage go back to original and the radio work again?

I don't see why not. I would imagine the mileage is in the dash display and changing BSI won't affect it, but I have never had the chance to play with it. If you paired the radio the the BSI it will need to be coded back to the original BSI for it to work again.

I swapped these this weekend and as the replacement BSI, key and ECU failed to even start the car, I had to swap back. Unfortunately, the odometer reading does NOT go back to original reading. It appears that the reading is kept in both the BSI and the display and they both synchronise to the highest value. Hence I'm the same position that I was at the start of the weekend, but with an extra 60,000 miles on the clock!
Is there any programming that needs to be done to the replacement ECU/ BSi kit to make it start the car? I tried programming in the injector codes but that made no difference. I'd assumed that if the kit of parts was functional, it should at least start the car?
Any Comments please.

MistyCottage wrote:Is there any programming that needs to be done to the replacement ECU/ BSi kit to make it start the car?

No programming needed, you need the BSI, ECU and key (transponder chip in the fob) to start the car.

Check for immobiliser problems with your lexia on the replacement BSI ECU and Key.

Use lexia to read for faults if it won't start.

This turned out to be a faulty ECU/ BSI replacement set. Purchased another set, and this runs the car fine, although it also showed there was no fault in the original ECU/BSI. (It does need setting up to talk to the other controllers in the car but this can be all achieved with a Lexia). So I now have gone back to the original ECU/BSI and purchased the equipment to bring the mileage correct again, and have a spare known good ECU/BSI and 2 keys to move on.

Hi,

I may end up going down the same route how much do you want for the ECU, BSI & Keys Eddy 07720 321 009

MistyCottage wrote:It does need setting up to talk to the other controllers in the car but this can be all achieved with a Lexia

Hi, could you explain how thus is done as I have a Lexia but am finding it difficult to find things like this. Thanks.

Chapster wrote:Hi, could you explain how thus is done as I have a Lexia but am finding it difficult to find things like this. Thanks.

Look in configuration, after selecting the BSI or whatever ECU you wish to configure - the BSI is a good starting point.


The screen shot from lexia shows BSI configuration options 'menu' for several parts of the C3
and this one shows the individual selection for various options - this one highlights the child safety door locking option, but also has the option to enable the alarm, rain sensor, brightness sensor etc.
You just need to look in all the menus to find what you are looking for if you don't know where it is. You may have to enable the same option in several different menus.

Thanks for that. I've found some menus under configuration but nothing that implies "recoding" a new module with its own ECU built-in, so that the other ECUs (BSI?) will accept it or be paired to it or whatever it is that these computers do with each other.

It looks like I might need to replace my ABS module as the Lexia claims the pump has failed on it. The little bit I found on google suggests that as the ABS module has an ECU built into it, it'll need "recoding" or otherwise pairing with the car in order to function and be part of the collective. I cannot see how I'd do that.

Chapster wrote:I've found some menus under configuration

These are what you need.

Chapster wrote:but nothing that implies "recoding" a new module with its own ECU built-in

If its not in the menu, then you won't need it (except for mileage adjustment and BSI to Engine ECU immobiliser coding as these are not supported by lexia). I think "recoding" is a general term that applies to some of the ECUs, but not all of them.

Chapster wrote:so that the other ECUs (BSI?) will accept it or be paired to it or whatever it is that these computers do with each other.

Connect the new part and if its not already listed as connected or 'present' then change the listed item from 'missing' to 'present' in all the menus that list it. Some require extra information, like the VIN in the radio or immobiliser code in the key or injector attributes in the engine ECU - but its all in the lexia menus.

Like this:

Chapster wrote:It looks like I might need to replace my ABS module as the Lexia claims the pump has failed on it. The little bit I found on google suggests that as the ABS module has an ECU built into it,

It does

Chapster wrote:it'll need "recoding" or otherwise pairing with the car in order to function and be part of the collective.

Says who? If you already have ABS, then the option will already be 'present'.

Chapster wrote: I cannot see how I'd do that.

You can't, if its not in the lexia menus.....