DTC U0121-87: Lost Communication With Anti-Lock Brake System (ABS) Control Module - Missing message: Action

Refer to the appropriate system wiring diagrams and check the anti-lock brake system control module power and ground circuits for open circuit, high resistance. Repair the wiring harness as necessary
Refer to the appropriate system wiring diagrams and check the FlexRay bus circuit for short circuit to ground, short circuit to power, open circuit, high resistance. Repair the wiring harness as necessary
Using the manufacturer approved diagnostic system, check the antilock brake system control module for related DTCs and refer to the relevant DTC index