Contents
This document contains information on:
General
Function requirements
Function
General
The upshift delay supports the exhaust gas cleaning function of the catalytic converter. The engine achieves in this connection a higher rpm range in the cold state and thus brings the catalytic converter more quickly to its operating temperature.
Function requirements
Engine management ON (circuit 87M)
Engine in operation
Coolant temperature at start < 35 °C
Vehicle speed < 40 km/h
Function
In the case of the upshift delay, the shift characteristic maps stored in the electronic transmission control are modified. The shift characteristic map is composed of upshift and downshift characteristic curves. They define the engine rpm range in which the transmission will engage the next higher or lower gear. The upshift delay adjusts the shift characteristic curves so that the gear shifts in the partial-load range take place at a higher engine speed, i. e. at a later point in time. This brings the catalytic converter more quickly to operating temperature and supports the exhaust gas cleaning also in the engine cold state.
Upshift delay is active for a maximum of 60 s and is entirely electronic.