DTC U0076-88: Control Module Communication Bus "D" Off Bus Off; DTC U0077-88: Control Module Communication Bus "E" Off Bus Off; DTC U0078-88: Control Module Communication Bus "F" Off Bus Off; DTC U0129-87: Lost Communication with Brake System Control Module "A" Missing Message; DTC U0155-87: Lost Communication with Instrument Panel Cluster (IPC) Control Module Missing Message; DTC U1170-87: Lost Communication with Brake System Control Module (ch2) Missing Message; DTC U1171-87: Lost Communication with Brake System Control Module (ch3) Missing Message [12/2024 - ]: Procedure

Pre-procedure1

1. None

   Procedure1

2. Clear the DTCs.

   Chassis > Trailer Brake Controller > Clear DTCs 

   Result

   Proceed to
   NEXT

   Post-procedure1

3. Turn the ignition switch off.

Result: 

NEXT 

See step  2

Pre-procedure1

1. Turn the ignition switch to ON.

   Procedure1

2. Check if the same DTC is output.

   Chassis > Trailer Brake Controller > Trouble Codes 

   HINT: 

   If a CAN communication malfunction DTC and a related sensor malfunction DTC are output at the same time, the CAN communication malfunction must be repaired before troubleshooting the sensor malfunction DTC.

   Result

   Result	Proceed to
   CAN communication system DTCs are output.	A
   DTCs are not output.	B

   Post-procedure1

3. None

Result: 

A 

REFER TO "CAN COMMUNICATION SYSTEM". Refer To  CAN COMMUNICATION SYSTEM (EXCEPT HEV) - DIAGNOSTICS - INTRODUCTION  , or Refer To  CAN COMMUNICATION SYSTEM (HEV) - DIAGNOSTICS - INTRODUCTION 

Result: 

B 

USE SIMULATION METHOD TO CHECK 

Refer to METHOD TO SIMULATE PROBLEM SYMPTOMS [12/2024 - ]