There are three actuator motors for the ABS brakes, one for each front brake and one for the rear brakes. the basic antilock system consists of a DC motor, drive gear subassembly, ball screw, nut, piston, and hydraulic check valve. If the ABS control module receives information indication that the left front wheel is about to skid, the left front for example, the solenoid bypass valves would close and the left front would retract the piston so that the hydraulic check valve closes. Brake pressure is then modulated by motion of the hydraulic piston under control of the ABS control module. If the motor is frozen, ABS will be disabled and the antilock telltale lamp will turn On.

Code 46 sets if:

Rear motor frozen/ESB does not release motor.

Code 86 will also set.

This code can only set during initialization.

Use Scan tool to perform ABS motor tension release special test before removing motor pack.

When the ignition is cycled On, the ABS module verifies motors are in home position.

The ABS system will initialize (run motors down then up) when the vehicle is driven at least 13 km/h (8 mph) after start-up.

Diagnostics are run for this code every ignition cycle.

When attempting to diagnose an intermittent problem, use the Scan tool to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem.

Select Malf History from Scan tool ABS menu.