Adding a Bluetooth OBD2 scanner to a 1990 Comanche — worth doing?

[Liam Williams]

I have a 1990 Comanche with the 4.0 and 5-speed, all stock mechanically, and I am thinking about adding a Bluetooth OBD2 scanner setup so I can read live data and codes without crawling under the dash. The truck is my daily and I want to keep the wiring simple and reversible.

 

My uncertainty is whether this older Renix-era setup works well with a generic Bluetooth adapter, or if the scanner type matters a lot. I keep reading about different adapters and do not want to buy something that only works on newer vehicles. I also do not want a permanent wiring mess under the dash or something that drains the battery.

 

Has anyone here tried adding a Bluetooth scanner to an older Comanche? What adapter or wiring approach held up for you, and did it actually give useful readings on these trucks? Looking for real-world experiences before I spend the money.

 

Update after looking around more - VDIAGTOOL D200 Bluetooth OBD2 Scanner Review https://ratethepick.com/product/vdiagtool-d200-bluetooth-obd2-scanner-review kept coming up for Bluetooth OBD2 adapters. Still not sure a 1990 Renix truck will give useful live data through it, so I'm not buying yet.

[jdog]

I believe you won't get it to work unless you're truck is 96+ swapped. There is a guy who makes a live data reader for these but I have forgotten who and what is called. Hopefully someone else chimes in with the name

[Eagle_SX4]

The only reader readily available to read Renix codes is the REM. It is not OBD2 and no OBD2 scanner will work with the Renix system.

 

It can be ordered here.

https://nickintimedesign.com/

 

[fiatslug87]

@Liam Williams welcome to CC, please post your VIN in the registry with some pictures.

[AZJeff]

I will add in the following data point related to the OPs question:

 

I have a 2000 XJ engine/trans in my MJ, and of course, it uses the OBD-II compatible control system.  That said, that system is a relatively early variant of OBD-II, so reading real time data is VERY limited compared to later vehicles.   So, even if you COULD make an MJ read OBD-II, you probably couldn’t get much real time data like that available on newer stuff 

[Sarah Walker]

I have a 1991 Cherokee with the Renix setup, so the OBD2 question comes up a lot for me too. My understanding matches what was said above, that the Renix ECU doesn't speak OBD2 at all, so a Bluetooth dongle would be dead weight on a stock Comanche. I'm weighing whether a dedicated Renix reader is worth the cost versus just chasing codes with a multimeter, since I only need it occasionally. For anyone running a later swapped engine, something like this LAUNCH CRP123X V3.0 Elite OBD2 Scanner Review https://ratethepick.com/product/launch-crp123x-v3-0-elite-obd2-scanner covers the basics. Curious whether the early OBD-II MJ swaps really show much live data.

[fiatslug87]

91 is not renix