'96 850R won't communicate with ECU

JimConley · Post by **JimConley** » 27 Feb 2016, 07:38

Hi there, first time posting I do believe. Bought the car last November or so and still working my way through bring it back to stage 0. Sadly it was pretty poorly taken care of.
A problem I've had since owning it is that I can't communicate with the obd2 port. I've tried autozone, someone with a serial port and another time I think. We could read other modules like abs and the tcm but not the ecu. The cig lighter works so that's not the issue
Any ideas what it could be?

Post by **polskamafia mjl** » 27 Feb 2016, 21:52

Does anything happen at all when a scanner is plugged in? If I remember correctly there is a connector under the center console where some if not all of the wiring for the OBDII port runs through. If you're not getting anything at all out of that port it may be disconnected under the center console.

JimConley · Post by **JimConley** » 28 Feb 2016, 06:00

I had I had someone look at my car with what must have been some Volvo software. It had boxes for any computer he wanted to loom at like abs, trans or what have you, but the ecu was grayed out and couldn't click on it. So I'm assuming the obd2 port works, but I'll have a look at it just in case.

Post by **misha** » 28 Feb 2016, 08:00

It have Motronic 4.3 engine management,so...if ecu examination was tryed with Vol-fcr....it will not work.
Try with a home made flash code reader since 4.3 is still producing flash codes.
It could be also that communication line was cut on purpose by previous owner.

JimConley · Post by **JimConley** » 28 Feb 2016, 11:48

I also had autozone try to read the code and it didn't work. Would a cheap elm127 reader work? Also, thread on a homemade? Do you mean the one with wire, switch and an led?

Post by **erikv11** » 28 Feb 2016, 11:54

Yes, wire switch and LED is the "homemade reader" that misha is talking about. If that can't talk to the ECU through the OBD port, then nothing can.

JimConley · Post by **JimConley** » 28 Feb 2016, 12:18

I'll give it go this week and see if I can get a read out that way. I'll report back. That's guys.

Post by **misha** » 28 Feb 2016, 13:52

I would check "k-line" before doing anything.

Post by **erikv11** » 28 Feb 2016, 15:00

misha what is "k-line" ???

Post by **misha** » 28 Feb 2016, 16:13

Communication line.
If it's broken somewhere in the system,from ecu to obdII port,ecu will not communicate with scanner.
European 850 from late '96 & '97 have chipped keys and immobiliser.That "k"line goes through immobiliser.
On U.s market cars,as far as i remember corectly,"k-line" avoids immobiliser and goes directly from ecu to obdII port.