Diagnostic port not communicating 1997 VS Series II

[StephenM]

Been running rich on RHS bank. Did the Earth at the nvm but no difference. Fooled around and spotted that a pin on the LHS O2 sensor was pushed up. Put it back in and it seems ok. I took it around to my local mechanic for him to hook up to a diagnostic doodad. There was no communication from the port. I then remember that when I went to get a new key programmed at the Holden dealer that they also could not communicate with the car. Any idea where to look? Thanks.

 

[woteva]

Check the wiring as it goes straight to the ecu.

Have you tried the paperclip trick to read codes ?

 

[StephenM]

Comes up 12. All clear.

 

[losh1971]

I had the same problem with a snap on unable to connect and same with my ALDL cable and laptop. Turned out the plug under the dash had tarnished up. Some RP7 and a bit of working the plug in an out and it came good.

 

[BlackVXGTS]

The attached charts may help you: