Chrysler Repair: Speed meter wont work, transmission control module, chrysler concord


Question
I have a chrysler concord 1995 (3.3) the speed meter is not working at all other gauges working fine, already replace the sensors of gear transmission but still the same problem.

Answer
Hi Zaib,
If you have replaced the output speed sensor and the transmission seems to be functioning properly, then I would have to conclude that the speedometer unit itself in the cluster is faulty or the that the instrument cluster board in which it is mounted is faulty as regards the wiring (metal traces) that connects the speedometer unit to the board. I would remove the cluster and check the solder joints of the speedometer unit where they attach to the circuit board, and reheat them with a soldering pencil, as one of them may be 'cracked' and not making good contact.
The speed information to operate the speedometer is digitized at the transmission control module and is sent on a common digital bus pair of wires all over the car, and then at the instrument cluster that information is sent to the speedometer unit. Because of it being carried on the common bus with all the other digital cluster data, and the rest of the data is getting to the cluster, I would conclude that it it right at the speedometer head itself that your problem occurs. If it were at the speed sensor or the transmission control module then the transmission would not shift properly.
There are 3 different types of clusters, so to tell you how to remove it I need to either know which type you  have; or I can xerox copy and postal mail you the pages that describe how to remove the cluster so as to examine/repair/ or replace the speedometer/circuit board.
So tell me a postal mailing address if you want those pages.
Roland