OBD plug wiring 94 850

skloon · Post by **skloon** » 26 Aug 2016, 17:20

So I have come to the conclusion after trying many obd dongles and scanners that there is something wrong with my wiring as I can't scan- Is there a simple wiring diagram that I can follow to figure out what wires in the plug go where on the ecu ?

Post by **misha** » 26 Aug 2016, 17:25

'94 models have obdI system.
They produce flash codes and their obdI system is under the hood.

skloon · Post by **skloon** » 26 Aug 2016, 17:31

It has the interior plug too and it did work before I did a manual conversion and RN swap- now I have switched to ME 4.4 and cant use OBD1

Post by **misha** » 26 Aug 2016, 18:48

I need more data....you can't just "switch" to different engine management without serious modifications.
'94 20v n/a cars use Jetronic engine management.Sensors are different,emissions,wiring...etc.

skloon · Post by **skloon** » 26 Aug 2016, 18:56

I swapped in an ME 4.4 ECU still using all the 850s other bits- is a turbo car- when I first swapped I used my automatic ecu then switched to a manual one- now I am using a slightly reprogrammed 4.4 one-

Post by **Ozark Lee** » 26 Aug 2016, 19:10

You can pull the schematics from:

http://www.volvowiringdiagrams.com/

As far as I know the OBD-II is the same between the 4.3 and the 4.4 but you may need to disconnect the OBD-I stuff to get to work.

Pull the schematics for a '98 70 series as well since that will be for a 4.4 for sure. I think the '97 has both the 4.3 and the 4.4 listed as well and it would be interesting to compare them for differences.

...Lee

Post by **misha** » 26 Aug 2016, 19:19

Lee was faster!

Yes....motronic 4.3 & 4.4 have the same communication "k-line" path via obdII.
Do you have communication to any module in the car?

Post by **tryingbe** » 26 Aug 2016, 20:03

Do you still have a M4.3 ECU? Put it in and see if you can get OBDII working.

When I used the m4.4 ECU on my 94 850 turbo, OBDII work just fine. No modification to the car's wiring whatsoever.

misha wrote:I need more data....you can't just "switch" to different engine management without serious modifications.

Yes, you can, with M4.3 850, using a M4.4 ECU.

Read.

http://m44.wikia.com/wiki/M44_Wiki

skloon · Post by **skloon** » 27 Aug 2016, 00:23

Same thing with the 4.3 no communication with ecu I will unplug the obd1 tomorrow and see what happens

Post by **misha** » 27 Aug 2016, 02:32

tryingbe wrote: Yes, you can, with M4.3 850, using a M4.4 ECU.

Read.

http://m44.wikia.com/wiki/M44_Wiki

If you read the thread more carefully from the begining,you would see that i thought he have n/a car...and UP TO '96 ,20V cars have Jetronic engine management.