DTC P17A4: Automatic Disconnecting Differential Motor Limit Switch Circuit [08/2019 - ]: Procedure

1. Disconnect the F47 4 wheel drive control ECU connector.
2. Disconnect the D1 A.D.D. actuator (differential vacuum actuator assembly) connector.
3. Disconnect the A6 skid control ECU (master cylinder solenoid) connector.
4. Disconnect the F51 ECM connector.
5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F47-8 (DL1) - D1-6 (DL1)	Always	Below 1 Ω
   F47-7 (DL2) - D1-5 (DL2)	Always	Below 1 Ω
   F47-2 (ADD) - D1-3 (ADD)	Always	Below 1 Ω
   D1-4 (GND) - Body ground	Always	Below 1 Ω
   F47-8 (DL1) or D1-6 (DL1) - Body ground	Always	10 kΩ or higher
   F47-7 (DL2) or D1-5 (DL2) - Body ground	Always	10 kΩ or higher
   F47-2 (ADD) or D1-3 (ADD) - 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 D1 A.D.D. actuator (differential vacuum actuator assembly) connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to A.D.D. Actuator (Differential Vacuum Actuator Assembly))

2. Disconnect the A6 skid control ECU (master cylinder solenoid) connector.
3. Disconnect the F51 ECM connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   D1-6 (DL1) - Body ground	Ignition switch ON	10 to 14 V
   D1-5 (DL2) - Body ground	Ignition switch ON	10 to 14 V
   D1-3 (ADD) - Body ground	Ignition switch ON	10 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE A.D.D. ACTUATOR (DIFFERENTIAL VACUUM ACTUATOR ASSEMBLY). Refer to  REMOVAL [08/2015 - ] 

Result: 

NG 

REPLACE 4 WHEEL DRIVE CONTROL ECU. Refer to  REMOVAL [08/2019 - ]