I have a 90 allante that is really giving me a hard time. I has about 40,000 miles and is rarely driven. I'm getting the system failure on the DIC. The defroster comes on and the temp stays at 75. I hear what sounds like the AC compressor cycling on and off. I pulled codes and came up with these E052,B333,4,5,6,7,B440,B552. I reset the codes and drove the car for about 15 mins. The system failure message went away. That was yesterday, today I started it and let it warm up for about 5 mins and the system failure came back w/the same symptoms. I pulled codes again and got these that say history B333,4,5,6,7 which are SIR,PCM,CCDIC,IPC and HVAC Serial communication failure. After doing some net reasearch here and a few other sites I'm going to check the CPS's part number to see if I have a problematic one. Anyone have any input on this or ideas other than the CPS? The car starts,runs, and seems to drive fine. If I do replace the CPS should it theoretically solve this problem. Could it be loose connections? ANY info would be greatly appreciated! Sorry so long! Thanks. ryancornell@comcast.net

Hello and welcome Ryan! :welcome:

I'm sorry that I personally can not help you, but I can direct you toward some folks that can. Try the following link and ask for some advice. These folks are the best and I've been a member since before I bought my Allante. I think you will find some great info there and perhaps you might decide to join the AAG. We still want you here, but for the specific advice you need, those guys are the best. Lets see some pictures of your Allante in the picture gallery.

http://66.34.30.72/cgi-bin/yabb/YaBB.cgi

Go to the Allante Forum on the Allante Appreciation Group's webpage: allante@pointers.com
...or... www.allante.us

If you own an Allante [I've have an '87 since 1997] you almost hafta join the Allante Appreciation group (AAG).
And, purchase a manual... about $40 online... but, invaluable if you're gonna work on your Allante... and you are! Trust me.

THE Allante expert is a nice fella named Dick Hussey:
allantesource@prodigy.net
Fixes 'em and sells parts... Florida based.
Rohner's is good too... www.allantestore.com... San Diego.

Good luck, it's a great car!! Misty

Hey Ryan,

I noticed you haven't been around lately, and wonder if the guys at the AAG site helped you out. Please update us when you can and post some pictures of your Allante please.

Hey Ryan,
I noticed you haven't been around lately, and wonder if the guys at the AAG site helped you out. Please update us when you can and post some pictures of your Allante please.

As sad as it seems I just now replaced the CPS and I'm still getting the "SYSTEM FAILURE" on the DIC. Any one have any new ideas??

I'll try to get some pics up soon.

Ok. A little update. As of right now I cleared the codes. The only code that comes up after the clearing is B448 ac refrigerant(which is low I believe). Right now the "system failure" has not come back. Whats happening now is that the defrost is automatically coming on. I shut it off but a short while later it turns itself on. This is after driving the car for about 5 mins and letting it idle for about 10 minutes. I also tried wiggling the wires around the computers without replicating the check DIC and saying "system failure" in the DIC. This is getting fun! :bonkers: :rolleyes2

Dropped the car off at a mechanic that had it for a long time trying to fix this problem. He could not fix it. Aside from ripping the entire center console up and testing EVERY single wire to see if there is damage I don't know what to do. He said that it seems like somehow the computers are losing communication with eachother. He checked the grounds and ran dedicated grounds among other things but with no change. Any one else deal with this?, or did I end up with the only car with this problem. It just sucks that I can't find anyone with similiar problems. Thanks. Ryan

:banghead: :banghead: :banghead: :banghead2 :banghead2 :wtf: :bulging: :shocked2:

If it were my car, I'd get a used BCM (BODY COMPUTER MODULE) from another 90 Cad Seville Or Eldo that has the same dash cluster type, i.e. digital donor for digital Allante cluster or analog donor for Allante analog dash cluster. My 88 deVille acted this way after miswiring an aftermarket radio. Swapping out the BCM fixed it. Yes, I also have an Allante, an 88. The CPS usually causes flickering displays or lack of displays. The newer part no. has better solder connections I'm told. Good luck, Bill.

Any one have this problem?

What we have done in a few instances is to have people send all their modules to us: BCM, ECM, CPS, DIC, IPC, SIR, and HVAC programmer. These modules communicate on the serial data line. The CPS providers regulated 7 VDC power to them. We install them in one of our test Allante's, hopefully get the same condition, and by process of elimination figure out which module is causing the problem. Usually the problem has been in one of the modules. If you have not already done so, you should run the on-board diagnostics to see if any stopred trouble codes may provide a clue as to what is happening.

I'm still having the same problems with the car. Everything seems ok then with climate control off it turns itself on with defrost,75 degrees and norm fan the dic say's system fault. I'm still getting a battery drain when it sits. I did find one thing going through the diagnostics. With the car not running ign on diagnosing through the ECM I'm getting a .0 Batt volts while the BCM reads 12.0 Batt volts. With the engine running at idle the ECM reads 13.5 Batt volts and BCM reads 14.2 Batt volts. I'm not sure if this means anything but I can only hope. If possible could someone do the same testing and see if they have the same .0 ECM batt results with the ign on engine off? I'm not opposed to trying a new ECM before this car may go to a Cadillac dealer to see if they can make sense out of it. Thanks in advance for any help!