Certification ECU Communication Stop Mode [10/2018 - 07/2022]: Procedure

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the certification ECU (smart key ECU assembly) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F44-1 (CANH) - F44-2 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 

Result: 

OK 

See step  2

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F44-18 (E) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))

2. Reconnect the cable to the negative (-) auxiliary battery terminal.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   F44-4 (+B) - Body ground	Always	11 to 14 V
   F44-15 (CUTB) - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)