S 600 Sedan (140.057) V12-6.0L (120.980) (1994)
Exhaust Gas Recirculation Control (EGR)
The EGR valves are controlled by the LH control units via the EGR switch-over valves (Y27/2 and Y27/3). 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 (N3/3) 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.