: E47



2010 tank
10-25-10, 10:29 PM
i know its the bcm-pcm data problem. just wanted to know which is which. i looked in the glove box and i see three computers, one in the middle(black), the top(silver) and the back(silver) of glove box. thanks for the help 85 fleetwood 4100

daniel58
10-25-10, 11:00 PM
I don't know if this will help as it is for a 90 Deville. The one farthest back to the right behind the glove box should be the ECM, the one on top the BCM and the one in the middle front is the Diagnostic energy reserve module (DERM) whatever that is. I'm not familiar with an 85 but they may be the same as a 90.

2010 tank
10-27-10, 02:02 AM
thanks, another question, just because i got that code does that mean that i have to replace it?

2010 tank
10-28-10, 01:40 AM
anybody, yes, no, depends. anybody had this problem before, what did you do? thanks

cadillac_al
10-28-10, 08:08 AM
If nothing is malfunctioning then there may be no hurry to replace the bcm. It is fairly common for them to fail so you should start looking for another one for when that day comes. on my 92 it is silver and I think it is laying on it's side behind glove box.

2010 tank
10-28-10, 05:07 PM
my car wont start, i dont think its getting spark, is getting fuel and the ignition coil melted. already replaced it but still nothing. so i dont know what to do

cadillac_al
10-28-10, 07:07 PM
Oh yeah, melted coil, I read that somewhere but i have never heard of it happening on these HEI's. I wouldn't know what to do either. So you already have a new coil and cap, I guess I would check to see if the distributor is getting 12 volts. I would highly suspect the ignition module and that may have been the cause of the coil failure. I don't think the BCM controls any of this so that problem shouldn't cause the car not to start. Make sure the battery is good and strong. That's all I can think of for now. Good luck.

cadillac_al
10-28-10, 07:10 PM
I was thinking this was an 89 but I see it's an 85. I know next to nothing about the 4100 but my advice should still apply.

2010 tank
10-29-10, 12:24 AM
thanks for the help and i also went and got a brand new battery, so ignition module huh. thats cheaper lol

daniel58
10-29-10, 06:57 AM
I think al is on the right track, its probably the module. The melted coil is a concern, al's advice to check the voltage at the distributor is important. Most cars even today start with 12vt and run with somewhat less (9vt) so if you continue to have problems with the coil melting after replacing the module, I would look a the available voltage at the distributor. This could be a problem with the ingnition switch or ballast resistor wire. The module is a maintenance item, good place to start.

2010 tank
10-29-10, 05:15 PM
appreciate it, just ordered it form auto zone free shipping

the recluse
10-30-10, 12:51 AM
The coil voltage is not controlled by the ICM. The ICM regulates voltage coming from the coil, not to it. The coil gets direct voltage (more or less) from the battery, meaning faulty coil windings=burned up coil, rare but not uncommon. That and maybe a faulty voltage regulator also. For kicks and giggles, have the alternator tested.

Check all your fuses and fuseable links.If good, pull a spark plug boot off and see if it arcs off the engine block while cranking the motor. If no....well....try all of the above and report back...

2010 tank
10-30-10, 01:03 AM
question about the coil. i just replaced it and i forgot where two of the three wires go. is it red to red and yellow/white to yellow/white? also the ground what do i ground it too?

2010 tank
10-30-10, 01:04 AM
I think al is on the right track, its probably the module. The melted coil is a concern, al's advice to check the voltage at the distributor is important. Most cars even today start with 12vt and run with somewhat less (9vt) so if you continue to have problems with the coil melting after replacing the module, I would look a the available voltage at the distributor. This could be a problem with the ingnition switch or ballast resistor wire. The module is a maintenance item, good place to start.can i check it without having the car running?

the recluse
10-30-10, 01:26 AM
question about the coil. i just replaced it and i forgot where two of the three wires go. is it red to red and yellow/white to yellow/white? also the ground what do i ground it too?

No wonder the car won't start, you have to have the coil hooked up for the thing to crank... :hitstick:

Red is positive goes to the "BATT" lead on the cap. White/yellow sits opposite side. Ground wire has an eye connector that screws under one of the four screws that hold down the coil to the cap...try that and get back to us...:suspect:

2010 tank
10-30-10, 06:03 PM
No wonder the car won't start, you have to have the coil hooked up for the thing to crank... :hitstick:

Red is positive goes to the "BATT" lead on the cap. White/yellow sits opposite side. Ground wire has an eye connector that screws under one of the four screws that hold down the coil to the cap...try that and get back to us...:suspect:lol my bad, i hooked it up i just guessed though and still didn't run, wanted to make sure i didn't hook them up wrong.