500SL (129.067) V8-5.0L (119.972) (1993)
Fluid Pressure Sensor/Switch: Description and Operation
Transmission Overload Protection Switch (S65)
PURPOSE
The transmission overload protection switch protects the shift elements of the automatic transmission from thermal overload. This can occur
during gearshifts under load in the high RPM range.
LOCATION
The overload protection switch is mounted into the transmission housing.
DESIGN AND OPERATION
This component is designed as a pressure switch and mounted into the hydraulic circuit of brake band "B1".
The switch is open at a hydraulic circuit pressure less than 1.8 bar.
The switch is closed at a hydraulic circuit pressure exceeding 1.8 bar.
If overload is detected, the ignition is retarded for approx. 400 ms to 5° BTDC to reduce engine torque during 1>2 or 2>3 upshifts. As this
enhances gearshift comfort, the measure is also adapted to 3>2 full load downshifts.