HT4100 4.1, 4.5, 4.9 Discussion, HT4100 SYSTEM PROBLEM E047 and B334 in Cadillac Engine Technical Discussion; While driving - suddenly the "Engine Control System" light comes on and "System Problem" is displayed on DIC. Speedo shows ...
While driving - suddenly the "Engine Control System" light comes on and "System Problem" is displayed on DIC. Speedo shows "0", gas shows "E", Trip odometer shows "0", actual milage is displayed, cooling fan goes to "High", and hot air is blowing.
I stop the car and try the ignition several time and suddenly everything goes back to normal. The above has happened a few times and the frequency interval is getting shorter and more frequent.
When things return to normal the following codes are stored
E047, E052, E055
B121, B127, B334, B335, B336, B337
Besides unplugging and reseating the connector, What should I look for?
Has anyone experienced this? Any input would be a great help
Please post year and model of car. I'm assuming an 82-84 Eldorado or Seville because of the B codes.
Almost all of the codes you're getting are data exchange related. Spray some contact cleaner on all the major connectors, ECM/BCM/Programmer/CCP/DIC and reseat them. Clean both ends of the primary ground cables under the hood too. A loose or bad ground can send these computers into a tailspin.
Not that you need it now, but you may want to start browsing eBay for a BCM for your car.
I purchased a BCM from eBay. I looked up diagnostic for "System Problem" under ccdic diagnostic, and the only possible part replacement is CCDIC, the BCM replacement does not come up in any of the diagnostic connected with "System Problem".
Is there a section of the diagnostics that could be elsewhere that could conclude with BCM replacement?
Is there any sensor when not operating properly that could turn on "System Problem"
The first things I checked were the battery, cables and grounds, they all checked OK. I had a pine hole leak in the radiator and I replaced the radiator. I removed the connectors for the BCM and CCDIC and sprayed them with contact cleaner and reseated them. I also jiggled the connectors when the "System Problem" is ON and it does not go away - that rules out loose connections. However, the "System Problem" persists. I don't think it is the electrical ground problem, I think some event is turning it ON. I say this because when the car is cold the car is NORMAL as the car is driven the "System Problem" comes ON and after some times it switches OFF and this cycle of ON and OFF continues, I think this problem could be temperature related.
Therefore, I am wondering what are all the possibilities that turns ON "System Problem" and go from there. The diagnostics for "System Problem" eventually boils down to replacement of the CCDIC.
I suppose this thread is too old to find out what the solution to the problem turned out to be, but, I have a very similar issue and similar trouble codes with my 86 Eldorado.
Quoting from above:
"While driving - suddenly the "Engine Control System" light comes on and "System Problem" is displayed on DIC. Speedo shows "0", gas shows "E", Trip odometer shows "0", actual milage is displayed, cooling fan goes to "High", and hot air is blowing."
While the problem doesn't come on until the vehilce has been driven for awhile, I really don't think that temperature is an issue. It's just that the problem doesn't happen often. I am getting B334,335,336,337 codes. Nothing current, all History. I've cleared them before, but they come back - usually on the next trip. The common issue between them seems to be loss of the data link circuit. And, since it is a loop, it seems it is lost at two separate points if I am understanding the manual correctly.
I figure if two of us are having the same problem intermittantly, there must be others getting the same codes too. I am thinking the BCM may not be the problem since the trouble codes I am getting are not random, but rather consistently the same. Does that make sense? I am thinking a couple of bad connections are the cause. Anyone care to support or dispute that theory?
I reset the codes and drove for awhile. The B337 code came back on. This is "Data Link Lost from the BCM to the HVAC Programmer." So I think I will start with that one. The data link loop connects 5 different modules together. I am thinking about running a new wire from the BCM directly to the Programmer module. Maybe even bypass the connectors with the wire just to see if the data link between the two is really the problem. I don't understand why they ran the circuit in a loop. Why not just run a separate wire from the BCM to each module directly? The way it is now, the data has to make its way through 5 connections in one direction and 10 connections in the other. I assume there are a few intermittant connections in the string.