I have a 1998 Chrysler Town & Country minivan with the 3.8L six cylinder engine. I have owned the van for nearly two months and a strange problem has me scratching my head. Here’s what happens:
In the morning when I start the van to leave for work, a portion of the instrument cluster does not work properly. The speedometer and gas gauge appear as they do with the key off. Also, the digital gear selection display shows that ALL gears are being used. Once the van is moving, it does not shift into highest gear, meaning that the van is running 5000 RPM at 45 mph.
Once I get to work, which is only two miles away, my van waits patiently while I work. When I come out for lunch or to leave for any reason, those problems all are gone when I get into the van and everything operates as it should. BIZARRO!!
The issue has popped up during the day, and I have accidentally discovered that using the automatic door lock buttons will cause the cluster to work and the transmission to shift into higher gear.
For the past week, the temperatures have been summer-like here in Central CA (it was 102 degrees today) and I have had none of the described problems since the temp warmed up. Has anyone heard of this at all??
It sounds like the trouble is due to a bad connection somewhere, possibly in a connector to the instrument panel. It may be due to a faulty ground connection also. You may be able to find the trouble by tapping on suspected trouble areas with a screwdriver handle while the trouble is occurring. You could also try disconnecting and reconnecting main connectors in the dash area to see if you can clear the trouble. Be sure to turn the ignition off if you do that, just to be safe.
Would a bad connection also cause the transmission issue? I realize that in the modern car, computers are prevalent and control a great deal of what happens in the car, but is it possible that something electrical could manifest into that as well? And then there is the temperature influence as well…
What ground should I check? The one at the battery terminal? Or somewhere else?
You probably will have to have a technician look at this. I am not sure if the Body Control Module can be accessed by a scan tool. If the computer can be scanned the source of the problem will be narrowed down significantly. There could be a problem with one of the inputs to the BCM, a communications problem with the Power Control Module and/or the Transmission Control Module, or the BCM itself.
One thing to do is check the fuses that supply the BCM and TCM. The problem with the transmission is related to ‘ALL gear’ lights illuminated. The TCM is going into ‘limp home’ mode because it does not know which gear the shift lever is in. When you restart the van and the problem is no longer present, the TCM can process commands correctly.
Hope that has helped.