DTC 66

If a motor circuit is shorted to battery, ABS will be disabled and the antilock telltale lamp will be turned On.

CODE PARAMETERS
Code 66 sets if:
^ Rear motor circuit is shorted to B+.

This code can set at all times except when a previous failure has disabled ABS operation.

Code 86 could also set and the brake telltale lamp will illuminate when the rear ABS motor is not in home position.

DIAGNOSTIC AIDS
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.

Check the tightness of the female terminal grip with a spare male terminal.

Motor resistance is less than 2 ohms.

Motor runs in both directions.