Volvo’s Hill Start Assist option for the I-Shift transmission isn’t entirely new, but it seems not to be well known. Available on VN, VT, and VHD trucks, it deals with the time lag seen on all automated manual transmissions between release of the brake pedal and driveline engagement. That lag means the truck will roll back some distance if it’s starting on a grade, however slight.
The Hill Start Assist option will reduce or prevent such rolling back and the safety risk it represents. The feature can also provide reduction of driveline component damage by minimizing shock loads during start-up on a hill.
It works by applying the vehicle brakes when in a forward gear and starting on an incline, or in a reverse gear starting on a decline, enabled by a dash-mounted switch. When it’s switched on, Hill Start Assist automatically activates when the truck is at a complete stop with the brake pedal fully engaged and the truck is in gear, forward or reverse. The triggering factor is the release of the brake pedal. Once Hill Start Assist is activated, the brakes are applied for up to three seconds or until the accelerator is pressed, whichever occurs first.
The feature is not available with vendor transmissions, of course, nor when the truck’s equipped with Meritor Wabco ABS or the basic instrumentation package.
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