Minimum Modules Necessary to Run an '89 Reatta?

[Guest Dan Gibbs]

Howdy Guys

I need to move my 89 Reatta to another spot for a large dumpster to come in for garage cleanout and I need to know which electronic modules are necessary for the car to run in order to move it to a spot in the yard for a few days.

I currently have the ECM, BCM, ECC, ECC-Controller/TSM, and Central PS modules removed in order to check out/cleanup/re-capacitor them. I was in the process of pulling the dash to clean out a large mouse nest behind the glovebox above the ECM and heater area. My steering column and basic dash are still in place.

Obviously the ECM will be reinstalled, but do I need the BCM too, the ECC too, etcetera? Also, may be a silly question, but do I need the speedo cluster installed also?

I need to know pretty quick if at all possible...

Thanks,

Dan Gibbs

[KDirk]

Dan,

I've never tested the theory (yet) but I would be pretty certain the ECM, BCM, and CPS are all required. CPS provides power for the logic in all the other modules, so it's required installation is a given. The ABS module also if you want any braking ability while moving the car, other than the e-brake. I think it will run without the IPC, as it is treated as a "slave node" in these cars, the BCM is the master node over all other modules and manages the data line, so without it there is no functional serial data line.

Of course, without studying the schematics, I can't be sure if there aren't critical signal lines that pass through other modules that might cause a no-start condition if they are left open by the absence of a missing module.

KDirk

[2seater]

Interesting question. I suspect it will run with just the ECM, plus the ICM/coil pack which supplies the initial spark. You may be breaking new ground if you find out what it takes.

[Guest Dan Gibbs]

No prob guys....I'll letcha know. I'll try only the ECM first, then add the CPS, and then add the BCM, and finally the ECC and controller. My thoughts say just the ECM should run it but it may need the CPS as KDirk mentioned above.

I'm gonna find out.

Dan

[johnemac]

Let us know also what the minimum amount of cuss words are needed

[padgett]

I'd venture ICM and ECM is all you'd need to start & drive a short distance. Need the Crank Position Sensor in place but not the Central Power Supply. Brakes will work without the EBCM just no ABS.

[KDirk]

Let us know also what the minimum amount of cuss words are needed

Yeah...that.

When working on cars (or most any big project) I have something I call the F scale, and it has nothing to do with tornadoes. In actual usage: "changing those cradle bushings is gonna be a 10 on the F scale!"*

*This quote not taken from real life (obvious to anyone who has done cradle bushings on an E platform car)

Keep in mind the driveway and garage may resemble a tornado zone after the job is done. I have also been know to scare the neighbors into their basement while working on the car.

Not being an expert on the Teves setup, I thought the EBCM was needed for the pump to run [and by extension for the brakes to work], but I will defer to padgett's expertise on the subject.

I did run my 88 with no mem-cal in it for a short drive while I was troubleshooting the problems with it. Talk about rough! Engine barely ran in limp-home mode.

KDirk

[Guest NEMO]

If you have the computers why not just plug them all in to the connections? Use duct tape when needed to hold it ?

[padgett]

Best to think of the Teves as two seperate systems, boost and ABS. The ABS needs OK from the boost system to work but not verse the vice. Both provide some input to the BCM but do not need it.

The Reatta is an early example of a computer car that can be seperated into independant functions which makes troubleshooting relatively easy.

[DAVES89]

About 2 years ago I was trouble shooting [ my idea of troubleshooting is throwing parts at it, which is why I go to the local U-pick] why my ABS light was staying on in the Red. I thought I would be smart and swap out the EBCM from the Black [system working perfectly] and put it in the Red. The light stayed on in the Red, so I swapped them back only to have the ABS light now come on in the Black. Being the simpleton that I am, I thought that I had damaged the ECBM when I put it in the Red. So I went to the local U-pick, got one and plugged it into the Black, still didn't work. Took the Black to my friend who couldn't get a reading thru the ALDI box and checked out the EBCM only to find that I had not connected it properly. That fixes the Black. That is how I learned that the brakes will work w/o the EBCM.

BTW the red needed new sensor leads. It also works now...

[Guest Dan Gibbs]

The results are in guys

To restate my original post text, "I currently have the ECM, BCM, ECC, ECC-Controller/TSM, and Central PS modules removed". I only removed the modules from the interior - nothing was removed from under the hood.

Well I reinstalled only the ECM and voila, an operating Reatta. It ran fine - fine enough to move it about 30 feet away, out of my driveway to under my shade tree.

Cheers guys,

Dan Gibbs

[wht89reatta]

Believe it or not that is some valuable info. Thank you for sharing your findings with us.