The AMT gearbox has made automatic cars affordable to the masses. Here is an understanding of how it has managed to do so, as well as an understanding of how it works along with its pros and cons.
The automated manual transmission is the simplest type of automatic gearbox. The system used by Maruti Suzuki is sourced from Italian automotive component maker Magneti Marelli. The Automated Manual Transmission module consists of an electronic Transmission Control Unit (TCU) and an electro-hydraulic system. The TCU is mated to the car’s ECU and comes with a pre-set range of information that controls gear shifts according to different driving situations. The TCU sends electronic commands through the electro-hydraulic system to operate the hydraulic actuator that carries out gearchanges inside the gearbox.
The system carries out gear changes independently without driver input. The driver can change gears manually too by putting the gear lever in manual mode and selecting gears. Irrespective of driving in automatic or manual mode, AMT systems have jerky upshifts. A way to work around this is to lift off the accelerator slightly whenever you want a gear change and the transmission will carry out a smooth upshift. Downshifting is much simpler in AMTs as you simply have to depress the accelerator pedal harder when you want to go faster and the system will make the transmission downshift a gear or two depending on the situation.
This type of AMT gearbox however does not have the ability to enable coasting. Which is why when you are stuck in crawling traffic or between speed breakers throttle response becomes very jerky as the gearbox will not upshift to second gear at those speeds. So, the moment you lift off even a little, the car will lurch. A way to get around this is to slot the gear lever into Neutral every time you need to slow down at a crawl, and then slot it back to D when you need to accelerate again. Doing this is very easy as the gear lever is free from any locking mechanism and of course there is no clutch pedal operation required.
AMT different gearbox modes
R – Reverse
N – Neutral
D – Drive