obd2 no communication to scanner

[BenGTI16v]

Hi all, Im having  abit of trouble with my golf as the abs light has just come on  so I plugged it into a scanner and it came up with no communication. I did a bit a research and found out that if you have an aftermarket stereo fitted this can give you problems, so ive tried scanning it withoutit connected aswell with no luck. I have battery voltage to pin 16 on the obd2 port but I dont know what else to test.

Car is a 95 mk3 gti 16v and im using a snap on verus

Any help appreciated thanks.

[ttelracs]

Same issue !
Handbrake light came on so popped up to see my cousin who has a hand held scanner and could get no reading at all. It stated it was unable to communicate or no link detected. I too have an aftermarket head unit fitter, a Kenwood of some sort which it came with and wonder if this is why no joy ?

No answer though !

[BenGTI16v]

I have tested some of the pins on the port and I have battery voltage to pin 16 a good earth at pin 7 I believe pin 4 in the k-wire which should give a voltage but only gives 0.01v

[BenGTI16v]

Same issue !
Handbrake light came on so popped up to see my cousin who has a hand held scanner and could get no reading at all. It stated it was unable to communicate or no link detected. I too have an aftermarket head unit fitter, a Kenwood of some sort which it came with and wonder if this is why no joy ?

No answer though !

Checked you brake fluid level? sometimes the little plunger thing for the senser sinks in the resovoir causing the light to come on.

[itavaltalainen]

What OBD scanner are you using? Which cable? VWs of the mid to late 90s have OBD2 sockets but are not OBD2 compliant, hence you need a VW specific tool. Other than that might be a wiring issue....

[BenGTI16v]

What OBD scanner are you using? Which cable? VWs of the mid to late 90s have OBD2 sockets but are not OBD2 compliant, hence you need a VW specific tool. Other than that might be a wiring issue....

Ive used a snap on verus and a snap on ethos both didnt work but they could connect to another mk3 golf I had in at work but that was a 1.4 97 plate.

[Ess_Three]

As far as I know, no Mk3 was ever fitted with a diagnostic line to the Stereo...it's just too early.
So changing the Head Unit won't cause you any problems.

[itavaltalainen]

It's not about a diagnostic line to radio. It's the speed signal for the gala function, if connected to some radios this can for whatever reason mess up comms with diagnostics. I suppose it can confuse the ECU.

[Ess_Three]

It's not about a diagnostic line to radio. It's the speed signal for the gala function, if connected to some radios this can for whatever reason mess up comms with diagnostics. I suppose it can confuse the ECU.

Is there a speed signal in the radio wiring harness on the Mk3?
There ism't on mine.

I thought Gala came later on, with the Mk4?

[itavaltalainen]

All mk3s should have gala signal. Pin 1 on ISO connector should be that