Central Locking Problem [With VIDEO] - Could it be the relay?

[GiveMeABreak]

BSI Reset / Battery Disconnect / Reconnect Procedure

[authorleon]

Prop the bonnet open.
Wind down one window (just in case the car locks).
Close the doors, but don't lock the car.
Wait 60 seconds for the BSI to do "house keeping".
Disconnect the positive terminal. Ensure the connector cant touch the positive terminal accidentally.
When you have done what you need to do, close the doors and connect up the battery.
Wait 60 seconds again and don't touch the car during this time (house keeping).
On some models the rear wiper motor might run after the battery is reconnected, so flip the wiper off the glass before reconnecting the battery.

Thank... Hmmm. So I have an issue here. The ECU is going to be out for a couple of days. So I cannot keep the window down. And way around that. I cannot think of any. Also, the car is parked on the street..

Thanks

[ozvtr]

Well the window down thing is just a precaution. It's a habit I get into. Just in case "something goes wrong" I don't lock myself out. As long as you have a key in your hand, the drivers side door lock should work. I say should, because the lock can corrode up.
The other doors can be locked by using the emergency lock just adjacent to the lock in the door. Look in your owners manual to see how to lock the car if the battery is flat or the fob is not working.
WARNING!!!! Be sure that the drivers door lock can be locked and unlocked by using the key in the door...first. If the lock is corroded you may lock yourself out of the car!!!

[authorleon]

Okay, I got it out.

I will be replacing the relay in a few days.

[authorleon]

Just to confirm, that is the right relay???

Thank you

[ozvtr]

I'm sorry but I can not find any details on the PCB's of the BSI. There are 2 relays involved. 1 relay is connected to pin13 of the 16pin grey connector and 1 relay connected to pin15. I cant tell you which is which. I.E. which is the "lock" and which is the "unlock" relay.
However, if the guy in the video says that's the relay...then I guess you have to trust him?

[ozvtr]

I did a bit more research and that does appear to be the relay.
That relay should be connected to pin 15. Pin 15 appears to go to the unlock solenoid of the door locks.

[ozvtr]

FYI. Most "electric" door locks use a motor. A motor is complicated, has spinning parts, carbon brushes, gears and so on. BUT it draws small amounts of current and produces little "Back EMF (Electro Motive Force...VOLTAGE)" and it can be quite powerful.
However, Citroen/PSA tend to use solenoids. Basically, electromagnets, to move a "bolt" to lock or unlock the door. This is nice and simple...However...it produces a lot of back EMF across the open contacts of the relay when you switch the power to the solenoid off. This damages and burns out the the relay contacts. In fact, this process is somewhat similar to what is employed to produce a spark across the gap of the spark plug!!!
There are ways to mitigate the damage (hint: diode) but, I am not here to tell PSA how to engineer their electronics!
Why it only seems to be the unlock solenoid relay that fails, I have no idea.

[authorleon]

Hey all,

Question. Are the boards soldered together or is it a plug?

[authorleon]

Hi, I need help identifying this damaged component.

ZOOMED IN AS MUCH AS I COULD

Please can someone help me with this, for sure needs to be changed

[authorleon]

I think it is a SJ2C Diode.

[authorleon]

If any one has an OLD BSI unit. More than happy to pay for this component.

Thanks

[Paul-R]

Both surface mounted and leaded versions appear to be available in the UK. Could find any on Ebay but a quick search threw up the names Farnell, Mouser UK and Digikey. I didn't investigate further.

[authorleon]

Hi,

FYI, it is a
Vishay S1J
https://www.vishay.com/docs/88711/s1.pdf


Old relay. It was a pain to get out. New one going in.

[authorleon]

FYI, All working now.

I have a donner BSI unit. If anyone wants any parts, PM me please.

Thank you