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.