body control module "98"

[photog3513]

Hi guys,

Very interesting reading. I picked up a 1996 Caravan at an auction through my employer. It was one of those "as is" deals.
Anyway, my wipers don't work, and I'm pretty sure it's the BCM.

If I unplug the battery for about an hour, will that reset the BCM? Or will that screw up other things?

I've started looking for another one on the web, but I was wondering if that would do anything?

Thanks,

Photog

[GMAC454]

it is my understanding that unhooking the battery will not do anything for the bcm, it is a flash type of non volatile memory, so it does not clear out after the power is removed from it. if it did the mileage and other setting would zero out on you. some of the sensors will clear, like the MAF and MAP for the engine, but not for the bcm. at least in all of the testing i have done.
sounds definately like the BCM on yours, if you need any info just let us know. thanks
GMAC454

[GeoDad]

I have a 96 Grand Caravan. The radio buttons function very intermittantly. Power works ok, but the others are very flakey most of the time, requiring several presses to do anything. Also, the blower switch recently refused to work on any setting but "high". Could these be BMC related also? From the previous posts in this thread, it seems so. The ECM was replaced in this vehicle about 4 months ago after it refused to start one day and the coil pack tested good (had fuel pressure, could hear the pump start up, but no spark, ECM change fixed it).

thanks,

GeoDad

[GMAC454]

I have not heard of your specific symptoms before. usually the wipers and or electric locks/security system is thefirst to have issues. but the radio could certainly indicate this. I have not chased the schematics on the blower system, if the blower system goes thru a relay (in the fuse box up front driver side under the hood) and that is good along with the fuse, then i would lean 90% at the BCM. give a call to a dealer and just ask for a mechanic and ask him if the blower controls are managed by the BCM if they say "yes" then i would even jack it to 99% that it is the BCM knowing that you checked all the other pieces (I.E. fuses, relays).
Remember to ask about the odometer reading on the BCM you get if you go used, cuz you are stuck with it. most reputable salvage shops know enuff to mark the mileage on the BCM when they yank it out. also you need to indicate if you have a security system (original) on the vehicle or not to get the right one. I hope that helps sorry i can't give you a 100% answer on that but like i said that is the first time i have seen only those 2 things as an issue. let me know how it works out... and good luck.

GMAC454

[farmer11]

the fan only working on high is caused by a bad resistor. Found under the hood on the firewall passenger side. Hard to get to!

[HeadlessHorseman]

Originally Posted by farmer11

the fan only working on high is caused by a bad resistor. Found under the hood on the firewall passenger side. Hard to get to!

Get a flashlight and remove your glove box door. You can see this resistor block by peering through the hole where your glove box door used to be, high up on the firewall. The Resistor Block looks like a heater element (four coils) and is about 1" x 3" - if you see ANY rust or corrosion, you should replace it. Get some band-aids... I gave blood (literally) and you might too... because getting the old one OUT of and the new on IN to the firewall (from inside the engine compartment) can be a challenge.

[GMAC454]

hey thanks guys looks like you have been thru that one before!. I will take note of that and thanks for jumoing in with great help.

Gmac454

[gromittoo]

Has anyone tried changing the resistors, to change the blower speeds? For really humid evenings, I like to have a "Dead Slow" blower setting.

Actually, considering how the BCM always resets the the Fresh/Recirculate mode to Fresh on startup, maybe I should address that issue first. I also object to the way the BCM forces you to use fresh when in defrost mode.

It is true that the defroster works slightly better in the Winter if fresh air is mixed in, I object to losing the ability to shut out the ragweed while defrosting in the summer. Given that every minivan has AC, there is no reason to force the van to run fresh air while defrosting in when the tempreture outside is above freezing.

I have a 2001 Chry Voyager lowline.

[fatlad]

My wipers seem to be possessed! I consider myself lucky when I can turn them off. Is this the BCM? If so, and I purchase a new one, what do I do about the mileage issue?

[B33p3r]

As far as the mileage, ask your relatives about the BCM recording the mileage. If it's true, ask them how the dealer feels about correcting the mileage if the BCM is bought from a junkyard. If the dealer is willing to correct it (if possible) have them look at the mileage before you change it out other wise I would have a notary verify it and put there seal of approval on it. I'm sure they too will want to verify mileage before the change out. AAA comes to mind.

[skotchrox]

My intermittant "ghost" wipers on '96 went to full-on and could not turn them off (had to pull the fuse). After changing the switch in the steering column, it had no affect and the BCM was the next suspect. I researched the options (new, used, etc...) on the internet, I found a place that will rebuild/repair your BCM in a couple of days for $145. Used ones are $100 and you still don't know what other problems you're going to have later with it. This way, they diagnose the BCM and repair it - no worries about the mileage/flash issue, no worries about what other problems you might have with a salvaged part. Found the service at Directauto.com. I'm pulling my BCM today and shipping it to them for repair.

[thowell]

how about a blower motor that only comes on once in a while and a gas gage that doesnt work under 1/2 tank and the wipers only work on slow and fast no inter. ... radio wasw changed but before it was the factory one turned off and on when ever it wanted

BCM???
T

[nosaj442]

I have a 96 grand caravan LE with 235k mi. i was having similar problems with my dash lights, speedo, radio, tach, pretty much everything was going on and off when ever it pleased for a while. i had thought it was the bcm also. at 150 bucks and up i thought id to more troubleshooting first. i called up a local auto electric shop and they recomended that i clean or replace my neg bat termial first before replacing the bcm. i removed the terminal and it didnt look that bad but i took a small file and some baking soda water and made it shine. also put on those red and green corrosion pads on the terminals and i havent had a problem since. its just a suggestion. im sure each case is different but just offering an idea. Good luck!!!

[GreendaleChrysler]

Hi,

I have a '99 T&C. I recently bought it to replace my '99 GC (THrew a piston rod). THe dealer (Honda) did not have reomte entry fobs. But, I still had mine from the T&C. So, I followed the directions found on the thread for reporogramming key fobs (See http://www.automotiveforums.com/vbul...d.php?t=217760).

I jumped the green wire to the body ground. The green wire was in the corner of the data module. There was a small spark. Now I'm in trouble.

The radio no longer works. THe interior lights, door chime, power locks no longer work unless the key is in the 'run' position. And no, it didn't put the keyless into program mode.

Based on this thread, it sounds like I might have a BCM issue. Is there a fuse somewhere I can check? (Radio fuse is fine.) Could I have created a problem in the wiring harness? Where do I go from here?

Thanks in advance, GreendaleChrysler

[2manylaptops]

Hi, I have a 99 caravan. I picked up another bcm for 20 bucks on ebay. I didnt match anything. I was trying to fix an engine light problem that didnt give me any codes. Well the bcm worked okay for the engine light but I lost my wiper washer and intermittent control. so I guess Ill have to put the old one back in and do a better job of matching. Also I didnt see any mileage difference when I put the replacement in. Anyway either the mileage was so close I didnt see it or Ill see something different when I put the old one back in. Very informative thread.