really weird data on the modis 2 reattas same problem

I work in a shop in battleground,wa and we have a 8/88 and 9/88 buick reattas same customer. heres the wied part when u hook them up to the modis the data show -40 on the map temp. 5000-6000 on spark advance and all kinds of crazy stuff like 6000rpm when its really idling. weve gone through pretty much all the grounds and cleaned them we even hook up a map directly to the comp and it still reads negative 40 we tried replacing the bcm and the pcm and did not solve the problems. any ides oh and the illumination on the touch screen doesnt work in one of them. we also had a chevy alero or something with the same 3.8 in it no touch screens or digital dash but it read the same on the modis for data so its gotta be a common problem vehicle still runns but not well. oh and the head lights start dancin up and down when u try to turn them on.

Welcome to the forum!

Instead of telling us so much about the diagnostic equipment and readings, I believe you would get better results here if you just tell us what symptoms the car is having and let us try to help you diagnose the problem. Rarely do you ever need fancy diagnostic equipment to troubleshoot a Reatta. The on-board diagnostics normally will tell you what you need to know. After reading your post I have no idea what the problem is. Is it hard to start? Is it missiing?

Have you checked for stored codes in the computer. If so what codes are you getting?

The software in the modis probably is not reading the data stream properly.

Better to use the diagnostics built into the CRT to diagnose what is wrong with the one with the working CRT.

Go here to get instructions on how to get into the diagnostics and read the codes. You can also see the status of the sensors and other helpful things by using them.

How To Access Trouble Codes - '88 & '89 Models - ReattaOwner.com

As to the blank CRT, can be a fuse, believe there are 3 that supply that function, the CRTC, the CPS, or very likely the CRT itself.

Headlights sound like switch or module or wiring issue rather than the motors which is the most common failure point.

Dancing headlights sounds like bad belcranks or rollers.

Doesn't sound like you work with old Buicks often.

My OTC 2000 with Pathfinder cartridge reads the diagnostics just fine.

88 and 89 PROMs are different, have you checked the PROM code ? Reatta does have a special PROM.

Snap-On Modular Diagnostic tool is good on late models but never tried one on a Reatta.

BTW the Olds Alero never had the 3800 but the early Intrigues did.