This bulletin applies to 2017-2019 Cadillac XT5 vehicles. The Service Park Brake message, red park indicator may be flashing and/or the amber parking brake wrench indicator may be illuminated. DTC C056D or C056E may be stored. If replacing the EBCM you may see programming error E6961. The cause may be resistance in the park brake circuit or park brake actuator.
Measure both rear park brake circuit resistance at the EBCM with the EPB actuators plugged in. The resistance reading should be 6.0 ohm or less. If resistance is above 6 ohm, inspect and repair the 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 brake caliper.
If you saw programming error E6961 after repairing wiring or replacing the actuator, you may need to power down the EBCM for over 5 minutes before programming.