Illumination Circuit [12/2013 - 11/2016]: Procedure

1. Check if the illumination for the radio and display receiver assembly, steering pad switch assembly, heater control switch or others (hazard switch, transmission control switch, etc.) comes on when the light control switch is turned to the head or tail position.

   Result

   Result	Proceed to
   Illumination comes on for all components except steering pad switch assembly.	A
   Illumination comes on for all components except radio and display receiver assembly.	B
   Illumination comes on only for steering pad switch assembly.	C
   No illumination comes on (radio and display receiver assembly, hazard switch, heater control switch, etc.).	D

Result:  2

B 

See step  5

Result:  3

C 

GO TO METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2013 - ] 

Result:  4

D 

GO TO LIGHTING SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2013 - ] 

Result:  1

A 

See step  2

1. Disconnect the F61 spiral cable sub-assembly connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   F61-9 (IL+2) - Body ground	Light control switch in tail or head position	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result:  1

OK 

See step  3

1. Remove the steering pad switch assembly.

   Refer to REMOVAL [12/2013 - ]

2. Connect a battery positive (+) lead to terminal 1 (IL+2) and a negative (-) lead to terminal 8 (EAU) of the steering pad switch assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component without harness connected (Steering Pad Switch Assembly)

   -

   -

3. Check if the illumination for the steering pad switch assembly comes on.

   OK

   Illumination for the steering pad switch assembly comes on.

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPLACE STEERING PAD SWITCH ASSEMBLY. Refer to  REMOVAL [12/2013 - ] 

Result:  1

OK 

See step  4

1. Remove the spiral cable sub-assembly.

   Refer to REMOVAL [12/2013 - ]

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component without harness connected (Spiral Cable Sub-assembly)
   *b	Steering Pad Switch Assembly Side
   *c	Vehicle Side

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   z4-1 (IL+2) - F61-9 (IL+2)	Center	3 Ω or less
   	2.5 rotations to the left
   	2.5 rotations to the right
   z4-8 (EAU) - F61-3 (EAU)	Center	3 Ω or less
   	2.5 rotations to the left
   	2.5 rotations to the right

3. After setting the spiral cable sub-assembly to the center position, rotate the spiral cable sub-assembly 2.5 times clockwise. Then while rotating the spiral cable sub-assembly 5 times counterclockwise, measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   z4-1 (IL+2) - F61-9 (IL+2)	Always	3 Ω or less
   z4-8 (EAU) - F61-3 (EAU)	Always	3 Ω or less

   NOTE:

   • Press and hold the lock located in the center of the spiral cable sub-assembly to rotate the spiral cable sub-assembly.
   • The spiral cable sub-assembly is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable sub-assembly may prevent the airbag from deploying.
   • As the spiral cable sub-assembly may break, do not rotate the spiral cable sub-assembly more than the specified amount.

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - BODY GROUND - RADIO AND DISPLAY RECEIVER ASSEMBLY) 

Result:  2

NG 

REPLACE SPIRAL CABLE SUB-ASSEMBLY. Refer to  REMOVAL [12/2013 - ] 

1. Disconnect the F69 radio and display receiver assembly connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   F69-10 (ILL+) - Body ground	Light control switch in tail or head position	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result:  1

OK 

See step  6

1. Disconnect the F70 radio and display receiver assembly connector.
2. Disconnect the F22 combination meter assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F70-5 (ILL-) - F22-12 (ILL-)	Always	Below 1 Ω
   F70-5 (ILL-) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [12/2013 - 11/2015]  Refer to  PROBLEM SYMPTOMS TABLE [11/2015 - 11/2016] 

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR