DTC 45

ABS Modulator Motor Pack:

There are three actuator motors for the ABS brakes, one for each front brake and one for the rear brakes. The basic antilock system assembly consists of a DC motor, drive gear subassembly, ball screw, nut, piston, and hydraulic check valve. If the ABS control module receives information indicating that the right front wheel is about to skid, the solenoid bypass valves would close and the right front motor 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 PARAMETERS:
Code 45 sets if:
^ Right front motor frozen/ESB does not release motor.

This code can only set during initialization.

DIAGNOSTIC AIDS

CAUTION: WHEN REPLACING MOTOR PACK DO NOT PLACE HANDS NEAR THE MOTOR/MODULATOR GEARS. THE GEARS MAY HAVE ENOUGH PRELOADED TENSION TO CAUSE PERSONAL INJURY.

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.

IMPORTANT: Initialization alternates between left front and right front each 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.