AWD Warning Light Remains ON [10/2014 - ]: Procedure

1. Check if the CAN communication system DTC is output.

   Refer to DIAGNOSIS SYSTEM [10/2014 - 09/2017] , or refer to DIAGNOSIS SYSTEM [09/2017 - 05/2018] , or refer to DIAGNOSIS SYSTEM [05/2018 - 05/2019] , or refer to DIAGNOSIS SYSTEM [05/2019 - 10/2019] , or refer to DIAGNOSIS SYSTEM [10/2019 - 07/2020] , or refer to DIAGNOSIS SYSTEM [07/2020 - ]

2. Check if the dynamic torque control AWD system DTC is output.

   Refer to DTC CHECK / CLEAR [10/2014 - 05/2019] , or refer to DTC CHECK / CLEAR [05/2019 - ]

   Chassis > Four Wheel Drive > Trouble Codes 

   Result

   Result	Proceed to
   Neither CAN communication system DTC nor dynamic control AWD system DTC is output	A
   CAN communication DTC is output	B
   Dynamic torque control AWD system DTC is output	C

   HINT: 

   When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding sensor.

Result: 

B 

GO TO CAN COMMUNICATION (HOW TO PROCEED WITH TROUBLESHOOTING). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 09/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2017 - 05/2019]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [05/2019 - ] 

Result: 

C 

REPAIR CIRCUIT INDICATED BY OUTPUT CODE (DYNAMIC TORQUE CONTROL 4WD SYSTEM). Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2014 - 05/2019]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [05/2019 - ] 

Result: 

A 

See step  2

1. Check if the 4WD ECU assembly connector is securely connected.

   OK

   The connector is securely connected.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT CONNECTOR TO ECU CORRECTLY 

Result: 

OK 

See step  3

1. Check the battery voltage.

   Standard voltage

   11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CHECK CHARGING SYSTEM. Refer to  ON-VEHICLE INSPECTION [10/2014 - ] 

Result: 

OK 

See step  4

1. Disconnect the I55 4WD ECU assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to 4WD ECU Assembly)

2. Turn the engine switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   I55-3 (IG1) - Body ground	Engine switch on (IG)	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Turn the engine switch off.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I55-4 (GND) - Body ground	Always	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to 4WD ECU Assembly)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  6

1. Reconnect the I55 4WD ECU assembly connector.
2. Turn the engine switch off.
3. Connect the Techstream to the DLC3.
4. Turn the engine switch on (IG).
5. Turn the Techstream on.
6. Enter the following menus: Chassis / Four Wheel Drive / Data List.
7. According to the display on the Techstream, read the Data List.

   Chassis > Four Wheel Drive > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   4WD Warning Light	AWD warning (multi-information display)	OFF or ON	OFF: Warning off ON: Warning on	-

   Chassis > Four Wheel Drive > Data List 

   Tester Display
   4WD Warning Light

8. Check the Techstream display condition of the 4WD Warning Light.

   Result

   Proceed to
   Display of the Data List remains OFF
   Display of the Data List remains ON

Result: 

Display of the Data List remains OFF 

GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - ] 

Result: 

Display of the Data List remains ON 

REPLACE 4WD ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - 05/2019]  , or refer to  REMOVAL [05/2019 - ]