Cadillac Repair: 1986 Eldorado Error Codes 4.1L, B337

Question
QUESTION: Bill,

I have a 1986 Eldorado with a 4.1L.  The computer says "system problem."  I think I have gotten into the system currectly and it gives me one history error code (EO52) and two current error codes - B336 and B337.  I just replaced the battery.

ANSWER: Hi Dan,

     The E052 means that the battery was disconnected or the ECM lost power. So you know why that code was set.

     The B336 and B337 are communications codes. What I would recommend is clearing the codes and see if any return. To do that you have the key on and press off and warmer on the climate control for up to 5 seconds or until the display changes and the computer enters the diagnostic mode. After the codes are displayed the push hi fan for yes when the ECM? appears. Then push low fan for no until clear codes is displayed and then push hi fan. Do the same thing to clear the BCM codes except when ECM? is displayed push low fan for no.

    Let me know if you need anymore help. Bill

---------- FOLLOW-UP ----------

QUESTION: Thank you Bill and welcome back, I really appreciate your help.

I cleared the codes and am still getting B337, Loss of Programmer data?

Answer
Hi Dan,

    I checked the bulletin and it really doesn't apply in this case. But I do need some more info. First off is there anything that doesn't seem to work propperly like dash lights or LED displays? When you push all the buttons on the climate control do they all work? Does the programmer control the temperature as it should? And is the mileage correct or is it all zeros?

    There is an HVAC fuse in the fuse block in the glovebox...make sure it is good and useing a voltmeter make sure when the key is turned on that you get at least 12 volts. Try the key several times. Power for that fuse comes from the ignition switch and maybe the switch contacts are getting burned and you aren't getting the propper voltage. Then with the key off remove the cover from the ALDL connector that is under the drivers side dash near the parking brake pedal. You should see it with the panel still on. If there isn't a cover on that connector reinstall it and retest for the code. If the cover is on remove it and then tern the key on and see if any other codes are stored like a 334.

    Its comming down to wires and connectors, the programmer or the central power supply that need to be eliminated as the cause of the code setting. Let me know if you need more help. Bill