Measures Output Shaft Speed:
The output speed sensor primarily monitors and measures the rotational speed of the output shaft of the automatic transmission. It detects the speed at which the transmission's output shaft is spinning.
Inputs for Gear Selection:
The TCM or ECU uses the output speed sensor input along with various other inputs, such as engine speed and vehicle speed, to determine the appropriate gear for optimal performance and fuel efficiency.
Shift Timing:
Based on the output shaft speed data provided by the sensor, the TCM or ECU can make adjustments to the transmission shift schedule. It calculates when to shift gears, ensuring smooth and efficient gear changes.
Slip Detection:
The output speed sensor helps in detecting transmission slip. When the difference between the engine speed and the output shaft speed exceeds a certain threshold, it can indicate that the transmission is slipping. This information can trigger diagnostic trouble codes (DTCs) and illuminate the check engine light.
Limp Mode Activation:
If the TCM or ECU detects abnormal output shaft speeds or transmission slip based on the sensor's input, it may activate limp mode. Limp mode limits the transmission to a lower gear or a specific gear range to protect the transmission from further damage.
Overall, the automatic output transmission speed sensor plays a crucial role in monitoring the transmission's output shaft speed. This information assists in optimizing gear selection, shift timing, slip detection, and limp mode activation, ensuring efficient and reliable operation of the automatic transmission.
