How To Proceed With Troubleshooting

WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

DTCs for the CAN communication system are as follows:
U0073, U0100, U0101, U0122, U0123, U0124, U0126, U0132, U0145, U1101.
Refer to troubleshooting of each system if DTCs regarding the CAN communication system are not output.

CHECK AND CLEAR DTCs
CHECK FOR INSTALLED SYSTEMS (ECUS & SENSORS) THAT ADOPT CAN COMMUNICATION)
1. Check which of the following is adopted: LEXUS Navigation System, dynamic radar/laser cruise control, and electronic modulated air suspension (See DIAGNOSIS SYSTEM ).
CHECK CAN BUS LINE (See CHECK CAN BUS LINE )
CHECK HAND-HELD TESTER VIA CAN VIM
1. Select "BUS CHECK" (See DIAGNOSIS SYSTEM ).
  Standard: All ECUS and sensors connected to the CAN communication system are displayed.
  NOTE:
  - The systems (ECUS, sensors) that adopt CAN communication vary depending on the vehicle and option settings. Check which systems (ECUS, sensors) are installed on the vehicle (See DIAGNOSIS SYSTEM ).
  - Non-installed ECUS or sensors are not displayed. Do not mistake them for being in the communication stop mode.
- NO: COMMUNICATION STOP MODE TABLE (See PROBLEM SYMPTOMS TABLE )
- Yes: Go to next step follow T/O
DTC COMBINATION TABLE (See PROBLEM SYMPTOMS TABLE )
1. Confirm trouble according to the combination of output DTCs regarding the CAN communication system.
  HINT:
  
  Previous CAN communication system DTCs may be the cause if CAN communication system DTCs are output and all ECUS and sensors connected to the CAN communication system are displayed on the hand-held tester's "BUS CHECK" screen via the CAN VIM.
CIRCUIT INSPECTION
IDENTIFICATION OF PROBLEM
REPAIR OR REPLACE
CONFIRMATION TEST
END