2002 Dodge Grand Caravan Sport 3.3

Symptoms:
Instument cluster warning lights randomly turn on and off.
Fuel gauge, Temp Gauge, and Tach stop responding randomly and independent of one another.
Headlights briefly turn off then back on.
Gear Selection indicator sometimes says your in all gears at the same time.
VTSS, Check engine light illuminates
Chime randomly chimes during normal operation of vehicle
Trac Off illuminates randomly
I'm not sure if this last one is related but sometimes when I lock the car with the fob the horn beeps to indicate it and sometimes the horn doesn't beep under the same conditions.

DTC's:
P1684 Battery disconnected recently
P1699 No CCD/J1850 Messages Received From The Climate Control Module (CCM)

Instrument Cluster Error Codes:
100.00 Loop-Back Failure
100.1 ABS Communication Fault
100.2 BCM Communication Fault
100.3 EATX Communication Fault
100.4 PCM Communication Fault
100.5 ORC Communication Fault
100.6SBEC/DED/MCM Communication Fault
400.1 ?

I replaced the battery in the van about a month ago which accounts for p1684. Note that the erratic symptoms were present at least 6 months before replacing the battery maybe a year. The car is used daily and functions well with the exception of the saftey problem caused by the brief turning off and back on of the headlights.

I've considered replacing the BCM with a used one with the same part number however there seems to be a lot of conflicting information out there regarding this. I had a Service Advisor at Dodge tell me today that you cannot "re-flash" a BCM. He went on to say that once a BCM is given a VIN number it cannot be written over with another VIN number so when it's flashed it will retain the characteristics of the original vehicle. He said this would result in loss of some of the functions of the BCM. He gave an example that you may be able to start and drive the vehicle bus some things may not operate correctly.

While at the dealer today I requested them to pull the codes off the BCM and to flash the BCM with the latest updates. The service advisor said there were no trouble codes on the BCM and flashing it did not elleviate any of the symptoms. He then said that his diagnostic computer was not able to communicate with the instrument cluster which indicates that possibly the instrument cluster and/or the BCM is bad. When he said that all I could see was dollar signs in his eyes. He offered to try and further diagnose the problem for another $135. I declined.

My huntch is to replace the BCM but I'm tired of working on huntches. I'd love to take it in and just say fix it but the truth is I can't afford it.

Is there a guru on this forum that can either confirm or reject my theory that the BCM is bad? If the instrument cluster were bad would it cause all of these problems? Can the BCM be bad without throwing a BCM code? Can a used BCM be "re-flashed" to ensure total functionality in a different car?

Please help!

 

Almost don't want to mention this because it happens so rarely on 4th genaration (your van) vans but try smacking the dash above the instrument cluster to see if you can induce or fix the problem. An all too common issue on 3rd generation vans is the well known cracked solder joints on the intrument cluster circuit board. The fix is to remove the cluster and reflow the solder joints that secure the connector to the circuit board.

Another problem found on 3rd gen vans is a melted connection at the HVAC (climate control) panel that kills the instruments. It's all to do with the data bus that intregrates all the electronics on the van. Your P1699 is a data bus code.

Other than that I've been reading of problems with wire bundles under the battery tray and in and around the IPM (fuse box), including corrosion inside the IPM creating all sorts of electrical problems including erratic instruments.

Ebay usually has Caravan instrument clusters cheap.

 

The cause of your problem is the data bus is crashing so none of the modules can communicate with each other. Any module can crash and cause basically the same problems. How long does each occurance last? Usually not very long which makes diagnosis very tough. If it is any module besides the BCM, you can unplug it and the problem will go away. The BCM has the termination so if the bus is down and you unplug it, it will still be down. You eliminate the other modules and then replace the BCM. BCM does have issues, I have had issues with the cluster and radio also. PDC issue are common too so don't jump to the BCM too quickly.

 

Update: I decided I was way over my head and figured I would go to the dealer for a definitive diagnosis. After they put it on the scanner they told me the BCM had no codes, and they couldn't communicate with the instrument cluster. They told me the problem could be with the instrument cluster or the BCM and suggested I may need to replace both. The dollar signs started adding up in my brain when they said If I paid them another $135 they would do another hour of diagnostic trouble shooting and maybe find the actual problem.

I'm ready to take a gamble as I can replace the instrument cluster and the bcm cheaper than it would cost to just get this thing properly diagnosed. This brings me to my question for the Guru's.

I have found a BCM with the same part number at a local junk yard. The service advisor at the Dodge dealership that I was at insisted that flashing the BCM would not change the VIN that was originally programmed into that BCM and therefore I would most likely loose functionality of certain things which are controlled by the BCM and the vehicle may not even run. I've read a number of posts on forums like this one which state that some have actually sucessfully pulled off the used BCM swap while some have lost some functionality.

Can you guys help answer these questions:

1. Based on the dealership's inability to communicate with the instruments cluster does this reveal any clues about what the problem may be.

2. I bought our van used and I thought I remember the previous owner telling me that the alarm had stopped working. If I have VTSS on my vehicle it doesn't work. Can you tell me how to know if I have it for sure?

3. Is there any danger in swapping BCM's? I thought I read once where a guy swapped a BCM and then put his original back in and the car wouldn't start. I can't afford a surprize like that.

4. Was the Dodge service advisor correct in saying that the VIN and the milage are not affected by flashing the BCM? Is there anyway to reprogram the VIN or the milage on a BCM?

5. I'm considering the BCM swap as a means to diagnose the problem. I figure I can swap one for about $75 and it may fix the problem. If I do loose some functionality at least perhaps it will fix my erratic light show in my instrument cluster. Then I would know for sure that the problem is the BCM and I could replace it with a new one if needed. Does this sound logical? Do you see any problems with my logic?

Thank you guys so much for helping out. The time you take to help a perfect stranger is appreciated.

Thanks,

TJ

 

I thought of another new symptom that may help narrow things down. Recently we've had the radio and the wipers stay on well after shutting off the car and getting out of it. I realize the radio stays on a while if you stay in the car but it's not supposed to stay on after you open and shut the door. For me it's seeming more and more like the BCM. If I can just figure out if my van is supposed to have VTSS (if it does it's not working), then I'll be ready to attempt the used BCM swap. Thanks again for any help.

TJ

 

I had some weird problems on my '05 Caravan several months back; mostly related to the keyfob and interior door lock controls not working. There were occasions when the instrument panel misbehaved, but not to the extent that you seem to have.

I tried the "favorite" trick of pulling and reinserting the IOD (ignition off draw) fuse. That worked, for a short while. I brought it into my Dodge dealer and they reflashed the BCM. No more problems. What your Service Advisor was undoubtedly talking about was that part of the BCM permanent memory that contains very important information with some Federal regulatory interest, such as the mileage.

There's no guarantee that a BCM re-flash will work to fix the problems that you are experiencing, and I think that using a different BCM will cause more problems than it will resolve. The good news is, the BCM reflash cost just a little less than the "additional" diagnostics that your dealer quoted.

I would stay away from BCM swaps, and instead focus on the actual instrument panel and finding out about the VTSS. The modules in the newer vehicles like the Caravan "talk" to each other too much to risk losing all under-hood communications.

 

(1) Start with the cluster, if you can't communicate with it, chance are it's junk and may be all you need

(2) Dealer can tell you if you have VTSS with your vin

(3) swapping BCM's is very dangerous

(4) The vin and mileage are not programmable except by a qualified repair facility. Remember it's a crime to tamper with the mileage

 

First, I am hardly the expert you are looking for. All my information is based mainly on what I've read on various forums and dedicated automotive websites over the last 8 years or so. The limited personal experience I've had with the subject at hand consists of the dealership changing the BCM on my 96 GC for a wiper problem many years ago and fixing an acquaintance's erratic instruments by re-soldering the mentioned cluster solder joints on his 98 T&C. There are experienced techs on this forum. Hopefully they will chime in or I should say keep chiming in.

1) It reveals there is a communications problem on the PCI data bus.

2) Your dash should have an "alarm" light that blinks several times as the system arms. Turn the key to on/run. All the dash lights should light up. You may see it then. Ask your dealership. They should be able to tell by the VIN # or some other source.

3) Yes! If you swap a BCM programmed with a security system into a van without one or visa versa, it can effect the PCM and keep the van from starting.


4) As to flashing - I don't know. Chrysler dealerships change BCMs all the time. The VIN# and mileage have to be reset every time otherwise there would be thousands of vans driving around illegally with modified mileage figures. I believe that's a function of their DRBIII scanner.

5) Yes, I see the logic. I've read about many doing the same. As mentioned watch the security system match up. As far as the cost, kind of a catch 22. That's $75 that could go towards having this done at the dealership. Then again they could change it and not fix it and still charge you. Then again, this problem sure sounds like the BCM is the problem. There are other possible culprits and I'm thinking of the previously mentioned A/C Heater control panel (HVAC panel) connection and the single data bus wire that connects everything on the data bus. A poor connection/damaged wire anywhere on the bus can effect the entire bus or just parts of it. See my previous post and take note of Tizzy1s PDC thought.

Here's one thing you can do in your driveway. Read and try post #16 titled "DIAGNOSIS AND TESTING - SELF-DIAGNOSTICS" in the "Tizzy1 and others DIY" thread at the top of the forum. This will test all the instruments and lights on the cluster. If this works consistently it may indicate your cluster is good.

Your second post about the radio and wipers points to the data bus and could be the BCM. **Just remembered another problem spot**. It just fixed a very similar problem for someone on another forum after several visits to a dealership. It concerns the wire bundle at the bottom of each power sliding door (if equipped). Disconnect each one at a time and see if it cures anything. As I said earlier - " There are other possible culprits... and the single data bus wire that connects everything on the data bus. A poor connection/damaged wire anywhere on the bus can effect the entire bus or just parts of it".

If you don't get your answers here try www.chryslerminivan.com or www.dodgeforum.com

 

Back to the vtss issue. I called one dealership and asked if it had VTSS according to the VIN. He said no it only has Sentry Key System which is different from the VTSS. I want to be sure so I called a different dealer and he told me it does have VTSS according to the VIN. Is there a simple way to tell like a hood pin that sets off the alarm? Or some other way?
Do I understand correctly that a BCM with the part # P04727072AE was used in Caravans with and without security and are merely programmed differently? Or does the part number on the BCM indicate having or not having VTSS? I'm very close to pulling the trigger on a used BCM, I just have to get this VTSS sorted out as I've heard horror stories of people making this mistake in a BCM swap. There's plenty of success stories out there as well. I hope to soon share my own.

 

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