2002 Caravan problem - electrical? BCM?

haweater · #1 11-30-2005, 11:23 PM

Hi all,
We have a 2002 Caravan, 80000km. Today, wife calls me at work, not happy, me man, me fix... right?
Soooo, dealer is too busy, can't take it 'til end of next week.
Turn the key to on... hear fuel pump run fine. Lots of clicking coming from the relay box under the hood. Odd humm/whir noise coming from top of engine (okay, so I'm not a mechanic, I need to work on my technical terms)
Start the van OK, idles up and down erratically..... even sitting still the speedometer jumps up and down. ALL of the indicator for which gear this thing is in are lit from Park to 1.
A friend who was a mechanic for a small Ford dealership said he's seen this in the F-dealer more than 15 times and it's the Body Control Module? How common is this, haven't come across it yet in the older posts.
What can I do to try to figure this out while I wait for the mech at the dealer to finish fixing all of the other Dodge things that should have been recalled?
Is there a way of getting an error code from this like I can with my Honda in about 3 seconds or am I going to be throwing my x-mas money to the wrong family's kids?
Thanks a pile.
Gord

B33p3r · #2 12-02-2005, 09:00 PM

Is the engine actually idling up and down or is it just the rpm gauge that's idling up and down?

haweater · #3 12-04-2005, 11:53 AM

Quote:

Originally Posted by B33p3r

Is the engine actually idling up and down or is it just the rpm gauge that's idling up and down?

It's actually the engine idling up and down, not just the tach.

B33p3r · #4 12-04-2005, 08:55 PM

I don't know of any scenario where the BCM would actually cause the engine idle to fluctuate. The PCM is responsible for the engine systems.
The PCM is responsible for displays of speed, tach, engine temp, coolant levels, PRD21 display!!!. My best guess is the PCM or a cheaper alternative to try first...Vehicle Speed Sensor. Good luck and post back your findings. I'm curious.
The BCM is responsible for lights, windows, locks etc etc.

bigoldchevytoo · #5 12-05-2005, 09:19 AM

Quote:

Originally Posted by B33p3r

I don't know of any scenario where the BCM would actually cause the engine idle to fluctuate. The PCM is responsible for the engine systems.
The PCM is responsible for displays of speed, tach, engine temp, coolant levels, PRD21 display!!!. My best guess is the PCM or a cheaper alternative to try first...Vehicle Speed Sensor. Good luck and post back your findings. I'm curious.
The BCM is responsible for lights, windows, locks etc etc.

Had one other person tell me that the BCM shouldn't affect the running of the engine. The error codes the thing is giving is 1282 & 1698.
Would the Vehicle Speed Sensor affect the idling of the vehicle when parked and result in the lighting up of all of the gear selector lights as well?

B33p3r · #6 12-05-2005, 09:33 PM

It can cause the idle to mess up because the PCM makes adjustments based on speed. If the speed sensor is sending false data, the PCM is making false adjustments to gas,air and timing. I can't say whether it would cause the gear indicator to mess up. I just know the PCM is responsible for selecting the gear display that lights up.

MT-2500 · #7 12-05-2005, 09:52 PM

code 1282 is for fuel pump relay control circuit.
code 1698 is no bus signal from trans computer.
If clicking is coming from relay box check all power circuits fuses and try switching fuel pump relay with on same no.
If you have acess to a good engine capable scanner there is some fuel pump test that can be run from scanner and you can check for trans computer communcating with the scanner.
MT

haweater · #8 12-06-2005, 11:51 PM

Quote:

Originally Posted by MT-2500

code 1282 is for fuel pump relay control circuit.
code 1698 is no bus signal from trans computer.
If clicking is coming from relay box check all power circuits fuses and try switching fuel pump relay with on same no.
If you have acess to a good engine capable scanner there is some fuel pump test that can be run from scanner and you can check for trans computer communcating with the scanner.
MT

I'm now down to the point that the dodge dealer (whom I don't really trust) is about to have time to take a look at this van.
At the same time, I know a guy down the street who has a garage with the big fancy scan tool but specializes in big trucks and coaches.
My thoughts are to take the damn thing to the guy down the street for a scan and then let the so called dodge experts look at it and see if their opinions match.
What would you do?? I'm good at firefighting and many other things but when it comes to mechanics, there's not a helluva lot I can do beyond my much beloved '78 carbureted Chev. 'Puters are beyond my expertise.
Thanks,
Gord

MT-2500 · #9 12-07-2005, 08:57 AM

If the truck mechanic is willing to look at it let him have at it.
He may be able to find the problem for you orrhis scanner may show a code and point to the problem.
Let us know how it goes and if you get a code no post it back.
Good luck MT

bigoldchevytoo · #10 12-12-2005, 01:24 PM

Quote:

Originally Posted by MT-2500

If the truck mechanic is willing to look at it let him have at it.
He may be able to find the problem for you orrhis scanner may show a code and point to the problem.
Let us know how it goes and if you get a code no post it back.
Good luck MT

Scanned it and got codes P1698 [No transmission bus message] & P0500 [No vehicle speed signal].
I give up, it's going to the dealership and I'm crossing my fingers that they can find a way to put whatever repairs on powertrain only warrantee.
Thanks.

MT-2500 · #11 12-12-2005, 02:15 PM

The codes points to trans computer.
All of the computers are hooked on a bus communcation line and have to communcate with each other.
Hopefully your dodge dealer can find the problem.
Good Luck
MT

Talon mike · #12 12-15-2005, 05:13 AM

Quote:

Originally Posted by MT-2500

The codes points to trans computer.
All of the computers are hooked on a bus communcation line and have to communcate with each other.
Hopefully your dodge dealer can find the problem.
Good Luck
MT

Problem could be in TCM but, more than likely it is corrossion in IPM
(Underhood fuse/ relay box). Have also had problems with wiring harness
between IPM and TCM caused by rubbed through wiring insulation.
This problem should be a regular fix at your local dealer, they usually keep the relay box in stock. Good Luck!

bigoldchevytoo · #13 12-15-2005, 09:59 AM

Quote:

Originally Posted by Talon mike

Problem could be in TCM but, more than likely it is corrossion in IPM
(Underhood fuse/ relay box). Have also had problems with wiring harness
between IPM and TCM caused by rubbed through wiring insulation.
This problem should be a regular fix at your local dealer, they usually keep the relay box in stock. Good Luck!

I'll let you guys & gals know what comes out of the dealership.

haweater · #14 12-15-2005, 10:47 PM

Quote:

Originally Posted by bigoldchevytoo

I'll let you guys & gals know what comes out of the dealership.

Big oops. Forgot my login and password at home and had confuser here and at work set to remember login.... so I created a new one. In case you guys and girls are confused, bigoldchevytoo & haweater are both the same perplexed Manitoulin Islander. Cheers!

tmsmusic · #15 12-16-2005, 06:15 PM

I have same exact issue! I have been dealing with it for over a year. I just yanked my 2001 GC out of the local dealer shop because they are clueless! I have been told similar things about the BCM and PCM. Best guess was to replace both. Problem was only the dealer can reprogram them. I am going to another dealer nearby next week and asking them to just replace those parts and I will just be out of luck if it doesn't work. From reading your replies, mine has stuff acting up from both modules when the outside temp reaches 43 deg. I hope you have had better luck. I will check back for more info and will post my result as well.

TMS

POST REPLY TO THIS THREAD