I’ve tried shorting the GND and 10 conectors on my 1999 mk2 1.8iS to set the idle speed but it blew the “engine” fuse. Looking on Miata.net they say that for the 1999 Miata the GND in along the bottom line of connectors 3 along. Has anyone done this on the MK2? I’m nervous of frying my ECU by trying again.
Also does the “GND” mean ground or earth? in which case can I just jump it to the car’s earth or chassis?
Hope this helps[:)]
Yes that’s the mk1 diagram I found, but MIata.net has a different one for a mk2 showing the GND in the picture above as RGND or something similar, and the GND to the right of IG-
I have used this diagram on many occasions and have had no problems. I believe the mk2 diagnostic connector is identical to the mk1 and was not changed until the mk2.5 came on the scene with it’s obdi thingy[:)]
I checked with a multi-meter, both GND seem to lead to earth with the ignition off, but the one on the second line has a higher resistance with the ignition on, whereas the one on the bottom keeps it’s same resistance
See here. both GND’s do the same, also the same as grounding to the body.