AGS (Adaptive Transmission Control)
AGS (Adaptive Transmission Control)
The GS 20 adaptive transmission control feature automatically selects suitable shifting programs based on driving style, selected range, monitored signal activity and road/environmental conditions. Advantages to the AGS shift control include:
- Shift points adapted to the driving style
- Improved safety - no unwanted up shifting while in a tight curve,
- Automatic determination and selection of the winter program for better driveaway traction and reduced shift activity.
- Improved comfort - Starting in second gear in stop and go traffic.
The AGS can be divided into two functional groups:
1. Driver influenced features
2. Features that react automatically to the driving style and environmental conditions.
Driver Influenced Features Of AGS
The adaptive drive program is based primarily on throttle input from the MS 42.0 control module via the CAN bus. The calculated rate of pedal position change influences the selection of the shift points.
Moderate movement causes moderate downshifts while a quick application of the throttle initiates a downshift.
The GS 20 also monitors braking and kickdown request.
Economical driving: Shifter in D. Drive with slow application of throttle. This provides low and comfortable shift points providing high fuel efficiency.
Quick accelerator pedal activity automatically leads the GS 20 into the intermediate power mode. Based on this input data, the AGS automatically selects a sporty shift strategy.
Sport: Shifter in "D", shift points are higher to take advantage of the full engine performance. The sport program is also immediately activated by a kick down request or excessive braking.
The AGS driving programs are not adapted on a long term basis - nor is it stored in the GS 20 control module memory when the ignition key is switched off.
The GS 20 continuously monitors the driving style and adapts to meet the current driver requirements.
AGS Features That React To Operating Conditions
Stop and Go Driving: This feature is activated by a defined sequence of shifts which are as follows:
- Upshift from first to second - followed by a downshift from second to first - followed by another upshift from first to second. This is then followed by the vehicle coming to a complete stop.
After this sequence, the transmission will stay in second gear. The GS 20 AGS program has recognized stop and go driving and this function prevents excessive shifting during heavy traffic conditions. The second gear start is cancelled when:
- The throttle pedal movement exceeds limits (quick step on the pedal)
- The range selector is moved to P, N or R.
Curve Recognition: This feature is activated when the GS 20 detects a variation of front wheel speeds via the CAN bus. The Mark 20 EI control module broadcasts the wheel speed sensor signals and their speed variations for any control module programmed to monitor this condition. When curves are recognized, the GS 20 inhibits up shifting until the front wheel speed signals equalize indicating the vehicle is driving straight ahead. This feature enhances the vehicle handling characteristics when cornering at higher speeds.
Winter Drive Program: Wheel slip is calculated by the GS 20 based on wheel rotation data provided by the traction control system via CAN bus. The GS 20 modifies shift characteristics to match winter mode for better traction. When active, the transmission will start in second gear and the shift points are lowered. The purpose of this program is to improve the drivability of the vehicle with slippery road conditions.
Cruise Control Program: When cruise control is activated, the MS 42.0 control module communicates this status via the CAN bus. The GS 20 activates a program suitable for active cruise control operation preventing pendulum locking/unlocking of the torque converter and minimizes up/down shifting. Additionally, the MS 42.0 can request a downshift if the vehicle speed exceeds the set speed limit when coasting downhill.
Hill Recognition Program: The GS 20 activates this feature when it detects a high engine load condition at lower road speeds. When the vehicle is traveling up hill the shift points are raised to prevent repetitive up/down shifting.