Just had transmission rebuilt and the speedometer bounces when in gear. Or with foot on brake. It bounces more with lights and a/c heat blower on.
You may want to have the place that rebuilt your transmission take a second look. It would also be a good idea to have the TCM codes scanned.
ELECTRONIC PINION FACTOR
The transmission output speed signal supplies distance pulses to the powertrain control module (PCM), which are used to calculate speed and mileage. A pinion factor is stored in the transmission control module (TCM) in order to provide the appropriate distance pulses for the vehicle. The pinion factor is programmed into the TCM at the assembly plant.
Using the following steps, the pinion factor can be checked and/or reset using the DRBIII®:
- Select Transmission system, then Miscellaneous functions, then Pinion Factor. The DRBIII® will display the current tire size.
- If the tire size is incorrect, depress the Enter key and then select the correct size.
- Depress the Page Back key to exit the reset procedure.
Notes About Electronic Pinion Factor Features The nature of the electronic pinion factor requires that certain features must be taken into consideration.
- If no pinion factor is stored in an installed TCM, the vehicle speedometer will not operate, engine speed will be limited to 2300 RPM, and catalyst damage may occur.
- Selecting a wrong FDR or tire size will cause the speedometer to be inaccurate and will also cause any speed related features to operate improperly. Note: After replacing the TCM, you must reprogram pinion factor