96 Caravan Won't Start - VTA/BCM/PCM Issue?

[Steve Atkinson]

I have a 96 Dodge Caravan with the 3.0L engine. In an attempt to fix the famous wiper problem with these vans, I replaced the BCM with a junk yard replacement unit. The van that it came out of had a security system (VTA); my Caravan does not. After plugging the new BCM in, the alarm went off, e.g. horn blew and the lights flashed. I had to disconnect the battery to get it off. I immediately removed the BCM and put back in the original BCM. The van will not start now. I turns over and seems to catch and then immediately dies. I'm thinking the Powertrain Control Module (PCM) still thinks the VTA is still in alarm and is killing the ignition. How do I reset it? I already returned the new BCM to the junk yard.

[Iwork4Chrysler]

You cannot replace the BCM with one from another vehicle. The BCM contains your odometer, VIN and build configuration. You've now set a fault in the BCM and the VTA which communicate to each other over the bus network. Just see your local dealer and for about 1hr labour, they'll correct this condition. Please remember to have all available keyless entry remotes on hand at the time of service as they'll all need to be reprogrammed.
Your original problem will remain. Is it the front or rear wipers that are not working?

[Steve Atkinson]

The problem with the wipers is in the front windshield wipers. They have mind of their own. Turning on and off any time they wish. They stop in the middle of the wipe; they don't turn on at all; or don't stop when the switch is in the off position. I've replaced the multifunction switch and the wiper motor without success.

[B33p3r]

Check your wiper on/off relay and the wiring associated with it. It should be amongst the fuses under the hood

[Steve Atkinson]

Thanks for the suggestions on the wiper problem. However, the van does not start so I've got to get it started first.

I disconnected the battery for several hours to try and reset the Powertrain Control Module (PCM) without success.

According the Dodge shop manual, I put a light on the ignition coil supply line. The light stays on while I'm cranking which indicates that the ignition system is getting juice and the PCM is energizing the Automatic Shutdown Relay (ACD) as it is supposed to. Next I check the fuel pump relay curcuit. The relay checksout ok. With the fuel pump relay removed, I put a light on the ground circuit which is controled by the PCM. The light stays on while the engine is cranked which indicates the fuel system is getting juice. My next step is to check the fuel system components. However, I'm still thinking the PCM is shutting down the engine because I said above, when I crank the engine, it definitely catches and runs for about one second and shuts down. Interestingly, if I try a second time without moving the ignition key to the off position, it does not catch and just cranks.

Could the PCM being shutting down the fuel injector supply?

Can anyone help?

[Steve Atkinson]

I was told by a professional, non-chrysler, mechanic that most likely the BCM and the PCM will have to be replaced and reprogrammed. This is an expensive option. Will just reprogramming work?

[Steve Atkinson]

I got the junkyard BCM back and reinstalled it. I then put 665 ohms according to the shop manual on the door lock circuit and "fooled" the BCM to reset or turn off the alarm. The van started right up! However, after I reinstalled the original BCM, the van would not start - the same problem. I'm hoping that it just needs to get the PCM reprogramed.