Reasons for increasing speed when switching automatic transmission:
* Insufficient transmission fluid pressure:
*Low fluid level
* Clogged or faulty oil filter
* Worn or damaged oil pump
* Worn or damaged shift solenoids:
* Solenoids are responsible for shifting gears and regulating fluid flow. Wear or damage can cause delayed shifting and increased RPM.
* Faulty speed sensor:
* The speed sensor reports the transmission speed to the control unit. A faulty sensor may give incorrect readings, resulting in incorrect gear shifting.
* Worn or damaged friction discs:
* Friction discs provide traction between different transmission elements. Wear or damage can cause slippage and increased RPM.
* Faulty torque converter:
* The torque converter smoothes the power flow from the engine to the transmission. Faults may include slippage, which causes the RPM to increase.
* Transmission control unit (TCM) software errors:
* TCM controls the operation of the automatic transmission. Errors in the software can cause incorrect gear shifting and increased RPM.
Workarounds:
*Check the transmission fluid level and add fluid if necessary.
* Replace the oil filter.
* Switch the automatic transmission to manual mode and try to change gears manually. If shifting in manual mode occurs without problems, this may indicate a problem with the shift solenoids.
Permanent solution:
Fixing the problem will require professional diagnosis and repair by a qualified transmission mechanic. Typically repairs involve replacing faulty components such as shift solenoids, friction plates, or the torque converter. In some cases, the TCM may need to be reprogrammed.