Hi does anyone know if the ECU’s are plug and play, or are they paired to the BSI unit? I’ve been told by a good source the key is paired to the BSI unit and not to the ECU. 
Can anybody on this forum confirm this please.

The BSI & ECU are paired AFAIK, but you can get unlocked ECUs

The guy who told me the ECU and BSI aren’t paired was a car lock specialist.

The ECU is coded to the immobiliser, but as Cancunia said, you can buy unlocked ones (immobiliser deleted) from https://www.hdi-tuning.co.uk/ for under £200 with no remap.

Extra for a remapped and unlocked one. Check their ECU page. They also sell on eBay but are cheaper direct.

(22-05-2020, 03:48 PM)Chris_wynn Wrote:  Hi does anyone know if the ECU’s are plug and play, or are they paired to the BSI unit? I’ve been told by a good source the key is paired to the BSI unit and not to the ECU. 
Can anybody on this forum confirm this please.

In M59 motorola chip ecu firmware there is a line in program that asks BSI if key code is ok.
If BSI send OK , ECU opens injectors and you can start car.
In ecu firmware you can delete that line of code and you can start car without KEY code.

Of course you can change program in BSI to send OK , but it is a lot easier to change that line in ECU firmware

All you need is motorola chip programmer(90-120Euro) and HEX editor(free program).

best regards,
brajomobil

(22-05-2020, 04:40 PM)Chris_wynn Wrote:  The guy who told me the ECU and BSI aren’t paired was a car lock specialist.

It was true... up until 2000 when the Berlingo got the BSI. 

Until then the ECU lived in complete ignorance of the key code, the door lock controller lived in the side of the car(behind the panel next to the passenger sitting behind the driver), you had just a lumpy fuse panel hidden under the dash, and CAN-bus was only talk.   

No wonder that I intend to keep my 1999 Berlingo running for as long as possible.

So Brajomobil, thank you for your detailed answer, so by your reckoning what I was told is correct. The key is coded to the BSI unit and the ecu and BSI are not paired.
If my ecu has an internal fault and needs replacing, can I just buy a 2nd hand one off eBay plug and play style?

Regards Chris

If you buy ECU without "key check" than it is "plug and play".
Be sure to double check that with seller.

Best regards,
brajomobil

Exactly what we said to you earlier Chris, the ECU has to be unlocked and the immobiliser check deleted before it will work. Otherwise it will not authorise engine start.

This is confusing .com
Brajomibil quotes “In M59 motorola chip ecu firmware there is a line in program that asks BSI if key code is ok.
If BSI send OK , ECU opens injectors and you can start car.”

So this statement says to me that yes the ecu and bsi are paired as in they talk to each other, but if I installed a different ecu would it ask the bsi the same question about the key code and work?