This bulletin applies to 2018-2019 Buick Enclave vehicles. The Service Parking Brake message may be seen, the red Park indicator may be flashing and/or the amber parking brake wrench indicator may be illuminated. Codes C056D or C056E may be stored, and other ABS codes may be found.
Measure both rear park brake circuit resistance at the EBCM with the EPB actuators plugged in. If resistance is above 6 ohm, inspect and repair any wiring concern, or replace the EPB actuator as needed.
If the actuator is replaced, make sure that the O-ring is seated between the EPB actuator and the caliper.
If you find programming error E6961 after repairing wiring or after replacing an EPB actuator, you may need to power-down the EBCM for over 5 minutes before programming.