Possible reasons:
*Low transmission fluid level: Check fluid level, adding fluid if necessary.
* Transmission slippage: This can be caused by worn clutches, a weak pump, or a faulty solenoid.
*Transmission control module (TCM) malfunction: The TCM may provide incorrect instructions on the instrument panel display.
* Transmission Output Shaft Speed Sensor Malfunction: This sensor sends output shaft speed information to the TCM. A faulty sensor can cause false signals and cause the light to turn on.
* Contaminated Transmission Fluid: Dirty transmission fluid can clog hydraulic lines, causing low pressure and shifting problems.
*Wiring Issues: A lack of power or a grounding issue can cause transmission components to malfunction.
Actions:
* Stop in a safe place. If possible, place the vehicle in park (P).
* Check the transmission fluid level.
* Scan your vehicle for trouble codes. The codes will help determine the specific cause.
* Call a tow truck. Do not attempt to drive the vehicle if the transmission light comes on.
*Consult a qualified mechanic. He will be able to diagnose the problem and make the necessary repairs.
Important: Ignoring an illuminated transmission light can result in further damage and costly repairs.