Author Topic: obd2 no communication to scanner  (Read 15094 times)

Offline BenGTI16v

  • Not said much yet
  • **
  • Posts: 18
Re: obd2 no communication to scanner
« Reply #10 on: 26 May 2012, 21:24 »
All mk3s should have gala signal. Pin 1 on ISO connector should be that ;)
should i disconnect it if i have an aftermarket stereo?

Offline Ess_Three

  • I live here
  • *****
  • Posts: 3,123
Re: obd2 no communication to scanner
« Reply #11 on: 26 May 2012, 21:35 »
All mk3s should have gala signal. Pin 1 on ISO connector should be that ;)

There are two connectors, a brown 8 pin (speakers) and a black 8 pin (power, ground, lights dim, to antenna etc)
Where is the Gala signal?

UK Mk3s never had Gala equipped stereos...and I'm certain mine has no unused wires in the black plug.

Reducing my Golf count by the week....
..but gaining motorcycles.

Offline itavaltalainen

  • I live here
  • *****
  • Posts: 2,693
  • VCDS and VCP - fault codes, coding, VIM activation
Re: obd2 no communication to scanner
« Reply #12 on: 26 May 2012, 22:04 »
Just had a look at my 96 UK Golf, wt-bl wire on pin 1, but my  Euro LHD one had that as well. It's unused on my aftermarket Sony (adapter from ISO to head unit has no wire going to pin  1).
So you might not need to disconnect it. I'll look up wiring for diagnostics, my AAM does also not connect and the K409 adapter and VAG COM worked fine on my 2E.
2019 Seat Leon ST FR DSG 135kW - eclipse orange - 23k miles

Offline BenGTI16v

  • Not said much yet
  • **
  • Posts: 18
Re: obd2 no communication to scanner
« Reply #13 on: 26 May 2012, 22:48 »
Just had a look at my 96 UK Golf, wt-bl wire on pin 1, but my  Euro LHD one had that as well. It's unused on my aftermarket Sony (adapter from ISO to head unit has no wire going to pin  1).
So you might not need to disconnect it. I'll look up wiring for diagnostics, my AAM does also not connect and the K409 adapter and VAG COM worked fine on my 2E.

Appreciate all the help guys, As far as I can see without pulling the dash off theres no breaks in any wires anywhere, plugged in the oe stereo and still had no change in k-wire voltage. Does anyone know if I fix my abs problem e.g I find a wheel speed senser down will the llight go off or will I have to clear the codes?

Offline BenGTI16v

  • Not said much yet
  • **
  • Posts: 18
Re: obd2 no communication to scanner
« Reply #14 on: 26 May 2012, 23:07 »
Just had a look at my 96 UK Golf, wt-bl wire on pin 1, but my  Euro LHD one had that as well. It's unused on my aftermarket Sony (adapter from ISO to head unit has no wire going to pin  1).
So you might not need to disconnect it. I'll look up wiring for diagnostics, my AAM does also not connect and the K409 adapter and VAG COM worked fine on my 2E.

Appreciate all the help guys, As far as I can see without pulling the dash off theres no breaks in any wires anywhere, plugged in the oe stereo and still had no change in k-wire voltage. Does anyone know if I fix my abs problem e.g I find a wheel speed senser down will the llight go off or will I have to clear the codes?
Also I have noticed there is only 4 pins on my obd port 4,7,15 and 16 I would have thought there were more.

Offline Ess_Three

  • I live here
  • *****
  • Posts: 3,123
Re: obd2 no communication to scanner
« Reply #15 on: 26 May 2012, 23:16 »
Does anyone know if I fix my abs problem e.g I find a wheel speed senser down will the llight go off or will I have to clear the codes?

I think the ABS light will go out after a few minutes of driving, but the fault will remain stored until cleared properly.


Quote
Also I have noticed there is only 4 pins on my obd port 4,7,15 and 16 I would have thought there were more.

I'm sure that's correct.
Early Mk3s had the 2 x 2 diagnostic connectors, so only 4 wires make sense.
Diagnostics on Mk3s are fairly basic anyway.

Reducing my Golf count by the week....
..but gaining motorcycles.

Offline Bandit127

  • Here all the time
  • ****
  • Posts: 443
Re: obd2 no communication to scanner
« Reply #16 on: 27 May 2012, 07:23 »

Also I have noticed there is only 4 pins on my obd port 4,7,15 and 16 I would have thought there were more.
Is it possible you have have OBD 1.5? That would need an OBD 1.5 compatible scanner to work.
http://www.autos.com/aftermarket-parts/your-guide-to-chip-tuning-a-vw
Quote
Some 1994 and 1995 model year cars are equipped with an OBD-1.5 system which utilizes a 16-pin connector, but uses the OBD-I system.

Re pin 15 having 0.1V... This diagram shows the cable connector for OBD2. Pin 15 carries the RTS signal - so it is an input and gets its power from the reader. Pin 7 carries the data and will have about 6V if you set your meter to AC and the line is transmitting.
http://pinoutsguide.com/CarElectronics/obd2_simple_cable_pinout.shtml

Offline Ess_Three

  • I live here
  • *****
  • Posts: 3,123
Re: obd2 no communication to scanner
« Reply #17 on: 27 May 2012, 10:10 »

Also I have noticed there is only 4 pins on my obd port 4,7,15 and 16 I would have thought there were more.
Is it possible you have have OBD 1.5? That would need an OBD 1.5 compatible scanner to work.
http://www.autos.com/aftermarket-parts/your-guide-to-chip-tuning-a-vw
Quote
Some 1994 and 1995 model year cars are equipped with an OBD-1.5 system which utilizes a 16-pin connector, but uses the OBD-I system.

Re pin 15 having 0.1V... This diagram shows the cable connector for OBD2. Pin 15 carries the RTS signal - so it is an input and gets its power from the reader. Pin 7 carries the data and will have about 6V if you set your meter to AC and the line is transmitting.
http://pinoutsguide.com/CarElectronics/obd2_simple_cable_pinout.shtml


I suggest you ask about for someone local with VCDS (VAG Com) because if the car has either the 2x2 connector, or the full OBD plug, VCDS will talk to it.
I've never found a diagnostic equipped VW yet that I've not been able to interrogate using VCDS.

Reducing my Golf count by the week....
..but gaining motorcycles.

Offline BenGTI16v

  • Not said much yet
  • **
  • Posts: 18
Re: obd2 no communication to scanner
« Reply #18 on: 27 May 2012, 12:32 »
thanks for the replies everyone. As far as I can see Comparing my car to the diagram im missing pin 5 which I guess would be the signal ground? I have pin 4 which is the chassis ground or the other way around?? :huh:. I also have the unswitched live feed. Didnt know what pin 15 did till now, I will probably will head off to my local dealer or specialist to see if they can read it.

Offline itavaltalainen

  • I live here
  • *****
  • Posts: 2,693
  • VCDS and VCP - fault codes, coding, VIM activation
Re: obd2 no communication to scanner
« Reply #19 on: 27 May 2012, 12:49 »
you only need 4 wires, just opened up my adapter :)
2019 Seat Leon ST FR DSG 135kW - eclipse orange - 23k miles