First of all, this is an amazing site with some smart people and great resources...thanks to all who help. Did my best to research before asking the question, and found out how to get codes out of my 1998 SLS, which was a neat trick. All of my codes said "history" after them, which further searching tells me means that they're not CURRENTLY an issue, but that they happened somewhere in the last 50 ignition cycles, after which point they're automatically cleared from the system.

Assuming that's the case, it seemed to be a lot of codes, was just curious if anyone thought they might be symptomatic of a bigger problem...

B1327 "vehicle system voltage below 9.0 volts"
U1255 "class 2 communication malfunction"
U1064 Loss of communications with DIM
U1128 Loss of communications with IRC
P1520 Transmission range switch circuit
P1527 Transmission range to pressure switch correlation

(Again, all these with "history" after, not showing as current codes.)

It occasionally does a few strange things, like the radio going out, or "dinging" itself to death while I'm driving down the road with doors closed, seatbelts latched, etc (eventually shuts up)...seems to use a little too much oil, and seems like I can never get it aligned 100% (lots of wobble around 50-55 but fine slower and faster, even after "professional" alignments)...but otherwise this has been my favorite and most trouble-free car ever, and that's saying something, as many have came and gone. 65,000 miles, and I'd like to keep her around for another 200,000.

Any ideas?

First of all :welcome: to the forums! :wave:


Do not trust ANY code that is up there if code B1327 is present. When the system voltage drops below 9 volts then the modules can't function properly and they will throw out random codes. Because of that code I would check the battery cables to make sure they are not corroded and they are tight. If the cables are good then take the car to a mechanic to have the battery and alternator load tested. They should be able to check the alternator without taking it out.

As far as the wobble is concerned, that is more wheel/tire than actual alignment...

You may have tossed a balance weight, or have a tire that has slipped a belt and thrown itself out of balance... the 50/55 speed sensitivity is 100% indicitive of a dynamic balance issue.

Not that it couldn't be a mechanical looseness in the steering system, but you would most likely have noticed that.

:)