Dynamic Stability Traction Control (Dstc); Traction Control (Tc); Spin Control (Sc) - Volvo XC90 2004 Owner's Manual

2004 VOLVO XC90
If the BRAKE and ABS warning lights come on at the same time, this could indicate a fault in the brake
system.
Stop the vehicle in a suitable place and switch off the engine.
Restart the engine.
If both warning lights go off, no further action is required.
If both lights are still on after the engine has been restarted, switch off the engine again and check the
brake fluid level (see
If the brake fluid level is above the MIN mark, drive carefully to an authorized Volvo retailer and
have the brake system inspected.
WARNING!
If the fluid level is below the MIN mark in the reservoir or if a "Brake failure - Service urgent"
message is displayed in the text window: DO NOT DRIVE. Have the vehicle towed to a Volvo
retailer and have the brake system inspected.
pg. 95 Starting and driving

Dynamic Stability Traction Control (DSTC)

The DSTC system on the Volvo XC90 consists of a number of functions:

1. Traction control (TC)

This function is designed to help reduce wheel spin by transferring power from a drive wheel that begins
to lose traction to the wheel on the opposite side of the vehicle (on the same axle). TC monitors and
compares the rotational speed of the drive wheels. If one of the drive wheels shows a tendency to spin,
the difference in speed is immediately detected. This triggers the Anti-lock Brake System, which brakes
the spinning wheel until the difference in rotational speed is corrected.
TC is most active at low speeds, and a pulsating sound will be audible when the system is regulating
wheel spin. This is quite normal.
This is one of the DSTC system's permanent functions and is not affected when the DSTC button on the
center control panel is pressed.

2. Spin control (SC)

The spin control function is designed to help prevent the drive wheels from spinning while the vehicle is
accelerating. This is done by temporarily reducing engine torque to the drive wheels, which helps
file:///K|/ownersdocs/2004/2004_XC90/04xc90_06b.htm (3 of 17)12/30/2006 4:35:23 PM
page 126 for the location of the brake fluid reservoir).