DTC U0104-87: Lost Communication with Cruise Control Module Missing Message [11/2021 - ]: Procedure

1. Read each DTC and check the diagnosis pattern using the table below.

   Chassis > Front Recognition Camera > Trouble Codes 

   Body Electrical > Front Radar Sensor > Trouble Codes 

   Pattern	DTC output part name (Display on GTS)
   	Front Radar Sensor	Front Recognition Camera
   Pattern 1	U0104-87	U0235-87
   Pattern 2	U0104-87	-

   Result

   Result	Proceed to
   Pattern 1	A
   Pattern 2	B

Result: 

A 

GO TO FRONT CAMERA SYSTEM. Refer to  DTC U0235-87: Lost Communication with Cruise Control Front Distance Range Sensor Single Sensor or Center Missing Message [11/2021 - ] 

Result: 

B 

See step  2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the A94 millimeter wave radar sensor assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A94-8 (CA1P) - A94-7 (CA1N)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω
   A94-8 (CA1P) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
   A94-7 (CA1N) - Body ground
   A94-8 (CA1P) - +B	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
   A94-7 (CA1N) - +B

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect the cable to the negative (-) auxiliary battery terminal.
2. Using an oscilloscope, check the waveform.

   OK

   Tester Connection	Condition	Tool Setting	Specified Condition
   A94-8 (CA1P) - A94-7 (CA1N)	Ignition switch ON	1V/DIV., 100μs./DIV.	Pulse generation

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [11/2021 - ] 

Result: 

OK 

See step  4

1. Connect the A94 millimeter wave radar sensor assembly connector.
2. Clear the DTCs.

   Body Electrical > Front Radar Sensor > Clear DTCs 

3. Make sure that the DTC detection conditions are met.

   HINT: 

   If the detection conditions are not met, the system cannot detect the malfunction.

4. Check for DTCs.

   Body Electrical > Front Radar Sensor > Trouble Codes 

   Result

   Result	Proceed to
   DTC U0104-87 is not output	A
   DTC U0104-87 is output	B

Result: 

A 

END 

Result: 

B 

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [11/2021 - ]