The Car Care Clinic with the Dr John

98 Plymouth Voyager - Body control module

Yolanda, from Hastings

Question

Dr. John, I have been told that my ‘98 Plymouth Voyager needs a body control module. I have no working gauges, tach. or speedometer. The LED readouts for the odometer and gear selector only show half a display. They also remain lit when the key is turned off. This problem is not constant, sometimes things work normally. You answered another person some time back by saying to be sure that the vehicle really needed a BCM and not a new dash display. How can I be sure of what I need as parts here have to be ordered and are expensive, so I have to be sure?

Answer

Now there is good reason to be concerned, because Body Control Module (BCM) is not cheap and it cannot be returned after it has been installed. There is a diagnostic procedure that allows a technician to determine if the BCM is the problem or not. The problem with diagnosing a BCM is that you have to have a computer scan tool to communicate with and perform function test to the BCM. You did provide a good piece of information. The fact that part of the dash display stays active even after the vehicle is turned off is a good indicator that the BCM has lost touch with the rest of the vehicle and is wandering around in its own little world. But before paying the bucks I’d pay to be sure you’re replacing the right part.Good Luck!

Good Luck!
Dr. John