Operation CHARM: Car repair manuals for everyone.

Special Functions








In addition to the manually-selectable gear-change programs (ECON, SPORT, WINTER), the control module incorporates a number of pre-programmed functions which ensure that the correct gear is selected at all times based on the prevailing driving conditions. The functions vary with the different markets and engine variants.

A. When driving at high altitude, engine power is reduced because there is less oxygen in the air. The control module provides High Altitude Compensation by adjusting gear engagement times to suit the prevailing conditions, thereby maintaining high shifting quality.

B. If the gear selector is in position D with the mode selector set to ECON and the control module simultaneously senses that the throttle is closed but the road speed is increasing, (e.g. engine braking on a steep downgrade), downshifting to 3rd gear occurs automatically ("Down Slope Mode") with a resulting increase in the engine's braking effect. Down Slope Mode operates within set speed interval parameters. This function is available only on certain markets.

C. If transmission temperature increases abnormally as a result of heavy load under high ambient temperature conditions, the torque converter lock-up function is activated as often as possible (temperature controlled lock-up). This reduces both slippage and the generation of heat in the transmission. If the temperature drops below +20 °C (68 °F) the lock-up function will not be engaged. At low temperatures, the control module increases the transmission line pressure, shortening the engagement times.

D/E. The control module is also programmed with certain safety functions which prevent manual engagement of gears which are too low if the vehicle speed is too high. Nor can reverse gear be engaged if the speed exceeds approximately 5 km/h (2 mph)

F. In the event of a serious fault in the electronic system, the warning light on the instrument panel flashes, and the control module simultaneously goes into a special emergency program ("Limp-home"), which ensures that two forward gears plus reverse will always be available, but that gear-changing must be performed manually. This makes it possible to drive the car to a workshop for repairs.