DTC P163B: 4WD ECU Malfunction [08/2019 - ]: Procedure

1. Disconnect the F46 4 wheel drive control ECU connector.
2. Disconnect the B47 transfer shift actuator assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F46-8 (TM1) or B47-2 (TM1) - Body ground	Always	10 kΩ or higher
   F46-7 (TM2) or B47-1 (TM2) - Body ground	Always	10 kΩ or higher
   F46-2 (HM1) or B47-8 (HM1) - Body ground	Always	10 kΩ or higher
   F46-6 (HM2) or B47-7 (HM2) - Body ground	Always	10 kΩ or higher

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  2

1. Disconnect the B47 transfer shift actuator assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2 (TM1) - 1 (TM2)	Always	1.5 to 100 Ω
   2 (TM1) or 1 (TM2) - Body ground	Always	10 kΩ or higher
   8 (HM1) - 7 (HM2)	Always	1.5 to 100 Ω
   8 (HM1) or 7 (HM2) - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Transfer Shift Actuator Assembly)

Result: 

OK 

REPLACE 4 WHEEL DRIVE CONTROL ECU. Refer to  REMOVAL [08/2015 - ] 

Result: 

NG 

REPLACE TRANSFER SHIFT ACTUATOR ASSEMBLY. Refer to  DISASSEMBLY [08/2015 - ]