300SE (140.032) L6-3.2L (104.990) (1992)
Exhaust Gas Recirculation Control (EGR)
The EGR valve is controlled by the LH control unit via the EGR switch-over valve (Y27). This switch-over valve is activated at coolant temperatures
above 65 °C (149 °F) and only if the engine is between the idle and full load condition.
Transmission 2>3 Upshift Delay Control
To heat up the catalytic converter faster, the no/partial load upshifts from 2nd to 3rd gear upshift in the automatic transmission is delayed. If the engine
coolant temperature is between 0 °C (32 °F) and 50 °C (122 °F), the LH control unit will delay the upshift to a maximum of 15 seconds after engine
start-up. The upshift occurs at higher RPM, accelerating catalytic converter warm-up.
The delayed transmission upshift is controlled via the switch-over valve (Y3/3). Vacuum is applied to the control pressure cable vacuum element via the
switch-over valve.