850 t5 ecu

desclarke · Post by **desclarke** » 08 Oct 2020, 02:27

hi thanks for allowing me to join i have a question on the ecu which plug is a or b front or back. As i understand i need a wire from b36 to pin 7 to read fault codes but it depends which way you look at it
Cheers have owned this car for 21 years now great car

Post by **abscate** » 08 Oct 2020, 02:45

Welcome!

I’m guessing this is for a 1995 850?

Here is some info. You could use this to find the AB side by 12V presence.

viewtopic.php?f=1&t=77600

desclarke · Post by **desclarke** » 08 Oct 2020, 04:57

Hi thanks I've seen that diagram but its semetrical no front or back

Post by **Chuck W** » 08 Oct 2020, 13:09

desclarke wrote: ↑08 Oct 2020, 04:57 Hi thanks I've seen that diagram but its semetrical no front or back

That diagram tells you everything you need to know.

If you are looking at the ECU, the B-bank is on the right. If you're looking at the ECU plug(with it unplugged from the ECU), it's on the left.

The "top" of the ECU is the smooth cover side.

The "B" is the chassis side of the harness, and if you're looking down into the ECU box, it would be the connector towards the rear of the car.