GM Service Manual Online
For 1990-2009 cars only
ABS Reference Speed: The scan tool displays 0-255 km/h (0-159 mph). The average speed of all four wheel speed sensors.

Ignition Voltage: The scan tool displays 0-17 volts. The amount of ignition voltage available at the Electronic Brake Control Module (EBCM).

LF Wheel Speed: The scan tool displays 0-255 km/h (0-159 mph). The actual speed of the left front wheel.

LR Wheel Speed: The scan tool displays 0-255 km/h (0-159 mph). The actual speed of the left rear wheel.

RF Wheel Speed: The scan tool displays 0-255 km/h (0-159 mph). The actual speed of the right front wheel.

RR Wheel Speed: The scan tool displays 0-255 km/h (0-159 mph). The actual speed of the right rear wheel.

Switched System Battery Voltage: The scan tool displays 0-17 volts. The amount of voltage available to the VES actuator when the ABS relay is activated.

VES Failed: The scan tool displays Yes or No. Yes indicates a malfunction has been detected within the VES system. No indicates the VES system is operating to specification.