Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

[GiveMeABreak]

As xantia_v6 says - you must have a matched set of BSI and Engine ECU along with a new transponder chip - replacing the BSI is insufficient. The engine ECU is paired to the BSI and that can't be used with another BSI unless it is virginised.

[wheeler]

Central locking diagram as requested.

[napping]

Great. Thanks for that

[napping]

If you ask Wheeler very nicely he might be able to provide a diagram for the door locks. We might be able to nut out out how to get the door unlocked now that you have access to the BSI connectors. Disregard what I said before about the connectors for the door locks (previous post) the pin numbers were for the MK1. It's possible the pin outs were changed for the MK2.

Looking at the circuit diagram from wheeler for the central locking, I'm reading it as follows;
* For the passenger/left front door locks, there are 2 servos for the locking (I assume one servo locks and the other unlocks the door)
* The one servo uses Grey connector pins 13 and 15. The second servo uses pins 15 and 16.
* To power Servo 1 without using the BSI, I can run 12v through pin 13 on the grey connector whilst running pin 15 on the grey connector to earth.
* If Servo 1 doesn't open the lock, I can try Servo 2 by running 12v to pin 16 and earthing pin 15.
Does that look correct or am I likely to fry something

[wheeler]

One of the motors is the deadlocking motors. The other just changes the polarity to regular lock & unlock. Im typing on a phone just now so no chance of looking at pin numbers etc just now.

[ozvtr]

Central locking diagram as requested.

Is this for a C2? It appears to have 4 doors? The rear doors on a C3 can be locked independently to the front 2 (not sure that's relevant...but).
I would assume then that the front 2 doors have the same wiring as the C2? Or do you have a C2 diagram?

[GiveMeABreak]

That one isn't for a C2, so maybe Wheeler got the wrong one - it can happen with multiple requests.

This is the correct one for 'Napping's' C2:

[napping]

The 2 diagrams are the same in respect to the front doors and their respective pins, but it's good to have the C2 specific diagram - Thanks
One question I have... Where the locking relays on the BSI go to fuse F2 in the engine bay, does F2 connect to earth?

[wheeler]

My mistake, I selected a C3 by mistake. They are both almost identical electrically anyway.

[ozvtr]

As xantia_v6 says - you must have a matched set of BSI and Engine ECU along with a new transponder chip - replacing the BSI is insufficient. The engine ECU is paired to the BSI and that can't be used with another BSI unless it is virginised.

Swap the EEPROM?

[ozvtr]

One question I have... Where the locking relays on the BSI go to fuse F2 in the engine bay, does F2 connect to earth?

BSI, glove box. Yes looks like it. Remember, the relay set up is to reverse the polarity of the solenoids. However F15 is also protecting that circuit. Not sure what that's about. However I bet F2 has a lower value than F15. F15 might be connected to other circuits but F2 is only protecting the door lock circuit.

[ozvtr]

Looks like R6 runs the deadlock solenoids. R4A and R5B form a polarizing matrix for the door lock solenoids.

You only need to worry about pins 13 and 15. However I cant tell you the polarity. But if one way doesn't work, try the other.

[ozvtr]

R6 polarizes too, so you might need to activate the deadlock solenoids as well to unlock the doors? Sorry, don't know.

[napping]

A further thought on inspecting the BSI, BSM, etc. got me thinking about the condition of the various components. Due to Covid restrictions, the car has had long periods of inactivity. Although the BSM and BSI areas and connections all look pristine, the ECU connections are exposed and haven't had the usual warmth from the engine to help prevent corrosion, etc. Given the symptoms, is there any way the ECU could be responsible for stopping the BSI waking up?

[ozvtr]

While I cant rule anything out (I.E. something 'holding' the BSI in sleep mode) I have no idea what that might be!!
If any one has any idea please, speak up.
The closest is ECO mode BUT in the very least the little battery symbol on the dash should flash! The dash and central display still light up when you open the doors in ECO mode.
The BSI does seem to detect the ignition switch but obviously it's doing nothing about it.
I have thought about the BSI being held in sleep mode, or at least not being woken up. But there are too many independent 'wake up' inputs.
There are relays in the BSM (like R6) that supply power back to the BSI. Is it possible that the BSI 'wakes up' fires up the CAN BUS, talks to the BSM, the BSM sends power back to the BSI, BSI starts turning stuff on!? What is fuse F13 in the BSM for? That's only hypothetical. Seems over complicated to me to do it that way...but I just don't know.
It's a bit too late in the evening here for me to try severing the BSM from the BSI, but I might try that tomorrow. Unless some one pipes up in the mean time and says it wont prove anything?