DTC U0235: Lost Communication with Cruise Control Front Distance Range Sensor; DTC U1104: Lost Communication with Driving Support ECU [04/2013 - 10/2016]: Procedure

1. Disconnect the M1 driving support ECU assembly connector.
2. Disconnect the B8 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
   M1-40 (CA1P) - B8-3 (CA1P)	Always	Below 1 Ω
   M1-18 (CA1N) - B8-2 (CA1N)	Always	Below 1 Ω
   M1-40 (CA1P) or B8-3 (CA1P) - Body ground	Always	10 kΩ or higher
   M1-18 (CA1N) or B8-2 (CA1N) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  2

1. Disconnect the M1 driving support ECU assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Driving Support ECU Assembly)

2. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   M1-30 (B) - Body ground	Engine switch on (IG)	11 to 14 V
   M1-30 (B) - Body ground	Engine switch off	Below 1 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   M1-25 (GND) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BATTERY AND BODY GROUND) 

Result: 

OK 

See step  3

1. Disconnect the B8 millimeter wave radar sensor assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Millimeter Wave radar sensor assembly)

2. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   B8-5 (IGB) - Body ground	Engine switch on (IG)	11 to 14 V
   B8-5 (IGB) - Body ground	Engine switch off	Below 1 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   B8-1 (SGND) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - BATTERY AND BODY GROUND) 

Result: 

OK 

See step  4

1. Replace the millimeter wave radar sensor assembly with a new one.

   Refer to REMOVAL [04/2013 - 10/2016]

2. Perform millimeter wave radar sensor assembly adjustment.

   Refer to ADJUSTMENT [04/2013 - 10/2016]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [04/2013 - 10/2016]

   Body Electrical > Pre-Collision 2 > Clear DTCs 

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

   HINT: 

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

3. Check for DTCs.

   Refer to DTC CHECK / CLEAR [04/2013 - 10/2016]

   Body Electrical > Pre-Collision 2 > Trouble Codes 

   NOTE:

   When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.

   Result

   Result	Proceed to
   DTC U0235 and U1104 are not output	A
   DTC U0235 or U1104 is output	B

Result: 

A 

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE) 

Result: 

B 

REPLACE DRIVING SUPPORT ECU ASSEMBLY. Refer to  REMOVAL [04/2013 - 09/2020]