Clearance Warning ECU Power Source Circuit [12/2019 - 11/2023]: Procedure

1. Disconnect the H46 clearance warning ECU assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connector (to Clearance Warning ECU Assembly)

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   H46-1 (IG) - Body ground	Ignition switch ON	11 to 14 V*1 10.5 to 16 V*2
   H46-1 (IG) - Body ground	Ignition switch off	Below 1 V

   1. *1: w/o Stop and Start System
   2. *2: w/ Stop and Start System

   Result

   Result	Proceed to
   OK	A
   NG (w/o Stop and Start System)	B
   NG (w/ Stop and Start System)	C

Result: 

B 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

C 

GO TO STOP AND START SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2022]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ] 

Result: 

A 

See step  2

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H46-28 (E) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [12/2019 - 10/2022]  , or refer to  PROBLEM SYMPTOMS TABLE [10/2022 - 11/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR