VW Vento AT rolls back on slopes
8th Oct 2015 2:47 pm
Is it normal for the Vento AT to roll back on slopes before moving forward?
I recently bought a new petrol VW Vento AT. When stopped on a slope, the car has a tendency to move back before moving forward, without accelerating. The dealer claims this is not a problem, but I’d like your expert advice on this.
Anas Aman, via email
AAA Mechanically, a dual clutch or DSG gearbox is more of a manual ’box rather than a proper automatic, so some characteristics (like rollback) are akin to manuals. Traditional automatic gearboxes have a high stall speed (which means the engine can hold high rpms without actually moving forward), achieved by a torque converter. But since there is no torque convertor in a DSG, this is achieved through other means – ie, electronic control of the clutches.
A pitch sensor on the car determines whether the car is on a slope and sends a signal to ECU to engage hill-hold. Being a full-blooded manual transmission on the inside, the ECU needs some time to find the friction point (bite point) of the electronically controlled clutch (like a driver would normally need in a proper manual transmission car). So a rollback on a hill is quite normal before the clutch engages. This is one of the weaknesses of a twin-clutch auto gearbox and, unfortunately, the Vento doesn’t have an effective hill-hold mechanism to prevent it from rolling back. However, you can be rest assured that this issue is completely normal and there is nothing to worry about.