TRACS System

WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.

TRACS is a traction control system integrated with ABS system. TRACS system is engaged at all times, and can only be disengaged by switch on instrument panel.

If control module detects via front wheel sensors that one drive wheel is turning faster than another, TRACS closes the inlet valve and activates pump, applying brake fluid to slipping wheel's brake caliper. This builds pressure in brake circuit, applying brakes just enough to ensure maximum engine power is applied to drive wheel with most grip.

Control module monitors how much brakes are being used and calculates temperature in front brakes. If TRACS is engaged and temperature becomes too high, TRACS is disabled and TRACS warning light comes on. After temperature decreases, TRACS re-engages. ABS system is unaffected.