April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U0100: Lost Communication with ECM / PCM "A"; DTC U0101: Lost Communication with TCM; DTC U0123: Lost Communication with Yaw Rate Sensor Module; DTC U0129: Lost Communication with Brake System Control Module; DTC U0142: Lost Communication with Body Control Module "B" (07/2015 -): Procedure

READ VALUE USING TECHSTREAM (CAN BUS CHECK)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.

Enter the following menus: System Select / Can Bus Check.

Result

Result	Proceed to
All of the ECUs and sensors that are currently connected to the CAN communication system are displayed.	A
None of the ECUs and sensors that are currently connected to the CAN communication system are displayed, or some of them are not displayed.	B

Turn the engine switch off.

Result: B

B

GO TO CAN COMMUNICATION SYSTEM

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING (07/2015 -) )

Result: A

A

See step 2

CHECK DTC OUTPUT (FRONT RECOGNITION CAMERA SYSTEM)
1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Chassis / Front Recognition Camera / Trouble Codes.
5. Clear DTCs (Refer to DTC CHECK / CLEAR (07/2015 -) ).
6. Turn the engine switch off.
Result: NEXT

NEXT

See step 3
CHECK CAN COMMUNICATION SYSTEM
1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Enter the following menus: System Select / Can Bus Check.
4. Select "Communication Malfunction DTC" from the "CAN Bus Check" screen, and then select "Enter".
  OK
  
  CAN communication system is normal.
5. Turn the engine switch off.
Result: OK

OK

USE SIMULATION METHOD TO CHECK

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING (07/2015 -) )

Result: NG

NG

GO TO DTC CHART (CAN COMMUNICATION SYSTEM)

(Refer to DIAGNOSTIC TROUBLE CODE CHART (07/2015 -) )