850R no obd2

[Mstrshkbrnnn]

I recently purchased a 96 r, and its got a few faults. ABS light and TRACS light are intermittently on, but i know the cause for those, so im not too worried about it, but at startup, the service light will turn on as well, before shutting off shortly after. my coworker has got one of those crazy matco scan tools with volvo software installed on it, but for some reason, no matter how many times he updates his tool, it can never "connect" to my car. I'm assuming there is some connection malfunction somewhere along the line, but im not sure what to check for, or where to start. for a little background, the previous owner installed some shitty aftermarket head unit, and did an equally shitty job installing it; could he have messed a connection up in the process?

[Clemens]

the 96 and 97 Volvo OBD2 is kinda weird. most obd readers cannot communicate with it if I remember correctly. i always have a Volbo dealer read the codes if any appear.

the service light comes on after a year or xx.xxx miles. It reminds you of the annual service.
The lights to worry about are the dreadful blinking arrow and the lambda sign (might be a different icon for US models).

[matthew1]

What year 850 are we talking about here? Your profile lists a 1994 850, but the title says 850 R, which is a 1996 or 1997.

NM. I see your signature has a '96 854R.

A 1996 should connect. It is a fully functioning OBD-II system.

A head unit will not affect OBD.

[erikv11]

Yeah I agree, I would try a scanner that you know can connect to an 850 (or VOL-FCR etc.), before suspecting any problem with the car's OBD2. I suspect it is the scanner.

For the service light the fix is to remove the bulb.

[matthew1]

Go ahead and get yourself a cheap OBD-II code reader. They're under $20, and it'll pay for itself many times over with your three OBD Volvos.

My Autel cheapie OBD-II scanner works every time, almost ten years later.

[Mstrshkbrnnn]

I own a scanner just like that one Mathew. I'll try it when i get home. I was just concerned because, i assumed if a specialized scan tool failed to connect, it was an issue with the car

[Goupil]

Might be a dumb question, but do you even have power to the OBD plug ?

When I got mine it had a blown fuse, iirc the obd fuse is shared with the AC

[matthew1]

I own a scanner just like that one Mathew. I'll try it when i get home. I was just concerned because, i assumed if a specialized scan tool failed to connect, it was an issue with the car

Sometimes the simplest effort is the most successful. More advanced technology always equals more variables. Reducing variables is the heart of troubleshooting.

[Mstrshkbrnnn]

Might be a dumb question, but do you even have power to the OBD plug ?

When I got mine it had a blown fuse, iirc the obd fuse is shared with the AC

just checked the fuse, and yes, it is receiving power. when my roommate get back home im gonna use his cheapo scanner that Matthew was recommending, and i'll get back to the thread with the results.