ECU Power Source Circuit [11/2015 - 07/2020]: Procedure

1. Disconnect the F40 driving support ECU assembly connector.
2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   (F40)

   (F40)

   Tester Connection	Condition	Specified Condition
   F40-7 (B) - Body ground	Power switch on (IG)	11 to 14 V

4. Turn the power switch off.
5. Reconnect the F40 driving support ECU assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

Result: 

OK 

See step  2

1. Disconnect the F40 driving support ECU assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   (F40)

   (F40)

   Tester Connection	Condition	Specified Condition
   F40-28 (GND) - Body ground	Always	Below 1 Ω

3. Connect the F40 driving support ECU assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [11/2015 - 12/2018]  , or refer to  PROBLEM SYMPTOMS TABLE [12/2018 - 07/2020] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR