1993 Chyrsler Lebaron Speedometer

1st check Tires size wrong size tires may effect speedometer

Also have the Transmission Computer checked if you have the 4 speed unit. The tire size is programmed in with the Chrysler DRB3 scanner. It takes about five minutes to reprogram it.

Never tried with an aftermarket scanner like those that most independent repair shops use. I have the Chrysler DRB2 and DRB3 scanners. Some other repair shops have them but for sure the dealer will have them. If you were a regular customer at the very nice dealership I worked at, they would often send someone out at no charge to quickly make reprogramming adjustments. Under the Transmission Computer menu there is a screen where the tire size is selected from a list.

This only applies to the four speed transmission. The easiest way to tell is there will be a circle around the letter "D" on the shift indicator on the dash. That transmission uses two different speed sensors and the computer calculates road speed. If you have the three speed transmission there will be no circle around the "D". That one uses a single speed sensor with a gear that is chosen from a tire size chart in the service manual. The wrong gear will have the wrong number of teeth so it will spin at the wrong speed. You would need a smaller gear with fewer teeth so it will spin faster. The different size gears are different colors too.

When you talk with the people in the service department you are talking with people who are trained in working with customers, not with cars. They have rarely been there more than a few years. What they ARE familiar with is typing the mechanics' "stories" into the computer after the car has been repaired. Everything done to a car is documented by the mechanic. That is how they get paid. Until recently, the mechanic hand-wrote that story on the back of the repair order. When he turned it in, the service adviser you spoke with entered that information into the computer so it could generate a bill. That is how they know about many of the common problems. It also explains why they haven't heard of the procedure you asked about. That goes back to the early '90s and those cars were still coming in for service for a few more years. The people you spoke with most likely weren't working there at that time.

You will have better luck going right to the dealership and speaking with their transmission expert or any other mechanic who was there in the '90s. Another place that can help is a transmission specialty shop. They will have either the Chrysler scanners or some other one that can access the Transmission Computer.