HELP! I accidentally conected the Lexia 3 conector on chip backwards, pluged it in the car and car died

[Jay-Bruce]

Presuming the pinout on the motherboard of the lexia is the same as the pinout on the OBD2 plug, physically rotating the plug shouldn't see any new interactions with battery supply on 16 to signal ground on 5. The swapped pairings would be (new pin No) = 17 - (old pin number) so in the rotated plug orientation old pin 5 = 17-5 = 12 new pin. So, signal ground on 5 would have been connected to vender option on 12. If you have continuity from signal ground to battery voltage, something's really foofood in there. Regrettably I don't regard myself as much of an electronics guy, so I can't really offer you much in the way of very specific advice, or that which I do profer should be taken with a spoon of salt (not just a pinch).

With that cavaet out there, I'd be interested to see what a known good BSI does when metered for continuity over pins 16 & 5. I'd also be interested to see if this is perfect zero ohms continuity, or is there a small resistance between them, such as 300 ohms, which might suggest a pull up resistor on those lines? Although I'd have thought you'd be better served with a pull down resistor on a ground line? (remember I'm more mechanics / hydraulics, with a smattering of electrics and even less electronics) I'd also wonder is the continuity bidirectional, as in is it connected both ways, with red probe in 16 + black in 05 & reversed with red 05 black 16? If it's only connecting one way, that would suggest a diode in there linking those pins. If there is a diode there, what it's meant to do is way beyond me...

[Jay-Bruce]

Just had another thought on this, there's 22 wires going into that plug, with only 16 pin slots on the obd2 plug, of which only 11 potential pin slots on the OBD2 plug are populated, meaning there's 11 wires unaccounted for. This realisation means that my initial pin count rotatary thing won't be accurate. So we need to start again. Do a pin out of the plug that goes onto the lexia board versus the OBD2 cable end do your pin count the same way the OBD2 is layed out, which is:
01,02,03,04,05,06,07,08
09,10,11,12,13,14,15,16

So assign your pin numbers for the board end of that cable as it will be easier to rotate those numbers.
01,02,03,04,05,06,07,08,09,10,11,
12,13,14,15,16,17,18,19,20,21,22

Do that, and give me a list of what goes where
01 -- obd2 plug pin2
02 -- angry pixy gymnasium
03 -- led
04 -- angry pixy hair salon
05 -- obd2 plug pin 15
and so on and so forth, we will get a better idea of what got hooked up to what when the plug was rotated.

If you want to push ahead and see what went where, without having to wait on mydoing the rotation in software, your pin parings will be:
pin 1 to pin 22
pin 2 to pin 21
pin 3 to pin 20
pin 4 to pin 19
pin 5 to pin 18
pin 6 to pin 17
pin 7 to pin 16
pin 8 to pin 15
pin 9 to pin 14
pin 10 to pin 13
pin 11 to pin 12
pin 12 to pin 11
pin 13 to pin 10
pin 14 to pin 9
pin 15 to pin 8
pin 16 to pin 7
pin 17 to pin 6
pin 18 to pin 5
pin 19 to pin 4
pin 20 to pin 3
pin 21 to pin 2
pin 22 to pin 1

[AnthonyKnight]

3 years have passed i still did not managed to fix my car, feel sorry every time i look it in the garage tried replacing ecu bsi imobilizer combo, tried replacing the bsm the abs unit and still nothing today i jumped back to try and work on it again now ihave a good lexia and other scan tools but still can't fix it,here are some of the mistakes it throws i replaced another abs today but lexia gives no dialogue also to dialoge to telematics i thinc and servo pump here are some photos from the error codes

[Kees]

In your case, all these errors only means that there's no voltage on critical points to the cpu's.
I read the post from the beginning.
You should try to get/find a wire diagram for the OBD port to the cpu's, or bring the car to an official Citroën dealer.
They can make contact with the factory in France to solve your problem.
Greetings,
Kees.

[xantia_v6]

Did you find wiring diagrams for your car?

[Kees]

I look again at all the errors, it seems you me, the the canbus hi/low not work, and I'm pretty sure that there one or more fuse's are broken. If i look at a wiring diagram with the BSI on it, I see several fuses connect to it.
Unfortunately this is from a C5X7.

[AnthonyKnight]

Here are the diagrams i extracted from the sedre last two photos are from the OBD socket

the other ones are from the abs unit, the suspension, tire inflation, and engine starting

[AnthonyKnight]

I forgot to mention that it seems only the driver assistance ECUs are affected—possibly because the old Lexia chip I used to cause this mess wasn't a full-chip version and could previously communicate only with certain ECUs.