Lexus ES: Control Module Communication Bus "A" Off (U0073,U0126,U0129,U0140,U0155)
DESCRIPTION
These DTCs are stored when the clearance warning ECU assembly cannot receive and recognize several signals via the CAN communication line.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| U0073 | Control Module Communication Bus "A" Off | Control module communication bus off | CAN communication system |
| U0126 | Lost Communication With Steering Angle Sensor Module | Lost communication with steering sensor | CAN communication system |
| U0129 | Lost Communication with Brake System Control Module | Lost communication with skid control ECU | CAN communication system |
| U0140 | Lost Communication with Body Control Module | Lost communication with main body ECU (multiplex network body ECU) | CAN communication system |
| U0155 | Lost Communication with Instrument Panel Cluster (IPC) Control Module | Lost communication with the combination meter assembly | CAN communication system |
HINT:
When 2 or more DTCs starting with "U" are output simultaneously, inspect the connectors and wire harnesses of each ECU.
PROCEDURE
| 1. | CHECK DTC OUTPUT |
(a) Clear the DTCs
Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs(b) Check for CAN communication system DTCs
Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes| Result | Proceed to |
|---|---|
| CAN communication system DTCs are output | A |
| No CAN communication system DTCs are output | B |
| A |  | GO TO CAN COMMUNICATION SYSTEM |
| B | | USE SIMULATION METHOD TO CHECK |
READ NEXT:
CAN Communication Failure (Message Registry) (U1000)
DESCRIPTION If DTC U1000 is stored frequently, duplicate the conditions that cause the problem symptoms and perform troubleshooting again even if the DTC is not output when rechecking for DTCs. DTC
Stop Light Relay Circuit (C1A4B)
DESCRIPTION When a stop light relay circuit malfunction signal sent from the electronically controlled brake system is detected by the clearance warning ECU assembly, DTC C1A4B is stored. DTC No.
SEE MORE:
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT:
Use the following procedure to troubleshoot the adaptive variable suspension system.
*: Use the Techstream.
PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP
NEXT 2. PROBLEM SYMPTOM CONFIRMATION
NEXT 3. INSPECT AU
Installation
INSTALLATION CAUTION / NOTICE / HINT HINT:
Use the same procedure for the RH side and LH side.
The following procedure is for the LH side.
PROCEDURE 1. INSTALL FRONT DOOR OUTSIDE MOULDING SUB-ASSEMBLY (a) Engage the guide and claw to temporarily install the front door outside moulding sub-as
