Stop (brake) lamp switch

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2007 Volvo V70, 2006 Volvo V70, 2005 Volvo V70, 2004 Volvo V70, and 2003 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Stop Lamp Switch

Courtesy of VOLVO CARS OF NORTH AMERICA.

The stop (brake) lamp switch is a single pole switch positioned at the brake pedal lever. It self-adjusts during its installation.

The stop (brake) lamp switch transmits signals informing the control module that braking has started. The control module interrupts any traction control and goes to standby mode for ABS / EBD control, which means that the control module can make more accurate calculations. If the control module does not receive a signal from the stop (brake) lamp switch, there is still ABS control available but the control is more vigorous at the start of the ABS control.

The stop (brake) lamp switch is supplied with power from the battery. When the switch closes, the stop (brake) lamp lights and the control module receives a signal that braking is occurring.

In All-wheel drive (AWD) cars equipped with TRACS, the stop (brake) lamp switch has two switches to ensure that traction control stops when braking. If a fault occurs in the stop lamp switch signal the traction control in the TRACS function is reduced from operating on all the wheels to operating on the front wheels only.

There are diagnostics for the stop (brake) lamp switch.