So, we have an OBD port on our trucks. My question is, what does it read? Does it read the RPM signal???

Thanks!

 

It might read engine rpm on the 92 and 93 trucks but I am not sure. The earlier trucks have no cps so it cannot know the rpm on those engines.

 

Engine RPM, preheater status, coolant temp on the autos, cruise control status, vehicle speed, intake air temp, throttle position on the autos.

 

Thanks. I just got a Droid phone and there is a blue tooth OBD port transmitter and a App to read it.

I know it works on the 2nd Gens but was wondering on the 1st Genners...

 

That sounds really cool. I am curious though, is there a Blue tooth transmitter available for the old-style diagnostic connectors like on the first gen, or is it just for the newer OBDII connectors? I would be a little surprised too, if the app had the capability of understanding the old stuff too, simply because each auto manufacturer was so different from each other before OBDII brought them together in 1996.

 

I am looking at it.

As verified by KTA on 1stgen, the old OBD1 reader did read RPM's. Looking to see if the app maker has something for the OBD1 and an adapter. If not, time to break out my programming skills...

 

Is there an OBD port on earlier trucks? Specifically, my '90? If so, where is it?

 

I know on the 92-93 they do, previous... ???

 

obd1 wasn't introduced until 1992 so I doubt the older trucks have anything. As far I have found there aren't any bluetooth connectors for obd1 I was looking for one to use with my car.

 

Jim, there isn't one. I swapped cabs on my first '91( and early non-ID'd ), and I can tell you for sure there was no such connection in that wiring harness.
cheers,
Douglas

 

I have one on my truck.

 

If the truck has a PCM, it should have a diagnostic connector. The early ones were located under the hood, on the wiring harness, right under the driver side hood hinge.