Scan Tool Method

Each motor can be manually turned ON for up to 5 seconds, at a current of 10 amps in forward or 6 amps in reverse. After running the motors, the command and feedback currents will be stored in the snapshot buffer. This information can be reviewed to determine if the motors are operating properly. The test below describes how the front motors will normally operate. The rear motor can be tested in a similar manner, except there will be only a slight pedal drop (bump) and rise during the test.
1. Turn the ignition switch to the OFF position.
2. Install scan tool.
3. Turn the ignition switch to the RUN position.
4. Select MISC. TESTS, MANUAL CONTROL.
5. Pump brake pedal until firm to deplete vacuum from power booster.
6. Depress and hold brake pedal.
7. "Release" the motor to be tested. The brake pedal should move smoothly toward the floor. As the pedal drops, the feedback current should momentarily drop to only a few amps (indicating motor movement) and then become equal to command current (6 amps). This indicates the motor is no longer moving since the piston has reached the bottom of the bore. Rough or "jumpy" pedal movement indicates an intermittent electrical connection within the motor.
8. With the brake pedal still depressed and at the floor, "Apply" the same motor. The brake pedal should now smoothly rise back to the top of its travel. The feedback current should momentarily drop to a few amps, then quickly increase to the command current (10 amps). This indicates the motor is no longer moving since the piston has reached the top of the bore (home position).