Steering Pad Switch Circuit: Procedure

1. Disconnect the radio receiver assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   FOR 10 SPEAKERS
   
   

   Tester Connection	Condition	Specified Condition
   H52-7 (SW1) - H52-6 (SWG)	No switch pushed	95 to 105 kΩ
   	Seek+ switch pushed	Below 2.5 Ω
   	Seek- switch pushed	313 to 345 Ω
   	Volume+ switch pushed	950 to 1050 Ω
   	Volume- switch pushed	2955 to 3265 Ω
   H52-8 (SW2) - H52-6 (SWG)	No switch pushed	95 to 105 kΩ
   	MODE switch pushed	Below 2.5 Ω
   	Voice switch pushed	2955 to 3265 Ω
   	On hook switch pushed	313 to 345 Ω
   	Off hook switch pushed	950 to 1050 Ω

   FOR 6 SPEAKERS
   
   

   Tester Connection	Condition	Specified Condition
   H47-21 (SW1) - H47-23 (SWG)	No switch pushed	95 to 105 kΩ
   	Seek+ switch pushed	Below 2.5 Ω
   	Seek- switch pushed	313 to 345 Ω
   	Volume+ switch pushed	950 to 1050 Ω
   	Volume- switch pushed	2955 to 3265 Ω
   H47-22 (SW2) - H47-23 (SWG)	No switch pushed	95 to 105 kΩ
   	MODE switch pushed	Below 2.5 Ω
   	Voice switch pushed	2955 to 3265 Ω
   	On hook switch pushed	313 to 345 Ω
   	Off hook switch pushed	950 to 1050 Ω

NG → See step   2 

OK → See step   4 

1. Disconnect the steering pad switch assembly connector.
2. Measure the resistance according to the value(s) in the table below.
   Fig 1: Identifying Steering Pad Switch Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   z4-11 (AU1) - z4-8 (EAU)	No switch pushed	95 to 105 kΩ
   	Seek+ switch pushed	Below 2.5 Ω
   	Seek- switch pushed	313 to 345 Ω
   	Volume+ switch pushed	950 to 1050 Ω
   	Volume- switch pushed	2955 to 3265 Ω
   z4-10 (AU2) - z4-8 (EAU)	No switch pushed	95 to 105 kΩ
   	MODE switch pushed	Below 2.5 Ω
   	Voice switch pushed	2955 to 3265 Ω
   	On hook switch pushed	313 to 345 Ω
   	Off hook switch pushed	950 to 1050 Ω

   TEXT IN ILLUSTRATION
   
   

   *A	w/ Telephone Microphone Assembly	-	-
   *a	Component without harness connected (Steering Pad Switch Assembly)	*b	MODE
   *c	Volume+	*d	Volume-
   *e	Seek+	*f	Seek-
   *g	Voice	*h	Off Hook
   *i	On Hook	-	-

NG → See step   6 

OK: Go to next step 

1. Disconnect the steering pad switch assembly and spiral with sensor cable sub-assembly connectors.
2. Measure the resistance according to the value(s) in the table below.
   Fig 2: Identifying Spiral With Sensor Cable Sub-Assembly Connector Terminal Identification

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   z4-8 (EAU) - H30-3 (EAU)	Center	Below 1 Ω
   	2.5 rotations to the left
   	2.5 rotations to the right
   z4-11 (AU1) - H30-6 (AU1)	Center	Below 1 Ω
   	2.5 rotations to the left
   	2.5 rotations to the right
   z4-10 (AU2) - H30-5 (AU2)	Center	Below 1 Ω
   	2.5 rotations to the left
   	2.5 rotations to the right

3. After setting the spiral with sensor cable sub-assembly to the center position, rotate the spiral with sensor cable sub-assembly 2.5 times clockwise. Then while rotating the spiral with sensor cable sub-assembly 5 times counterclockwise, measure the resistance as shown in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   z4-8 (EAU) - H30-3 (EAU)	Always	Below 1 Ω
   z4-11 (AU1) - H30-6 (AU1)	Always	Below 1 Ω
   z4-10 (AU2) - H30-5 (AU2)	Always	Below 1 Ω

   NOTE:

   • The spiral with sensor cable sub-assembly is an important part of the SRS airbag system. Incorrect removal or installation of the spiral with sensor cable sub-assembly may prevent the airbag from deploying.
   • As the spiral with sensor cable sub-assembly may break, do not rotate the spiral with sensor cable sub-assembly more than the specified amount.

   HINT: 

   • Removal. Refer to REMOVAL [08/2012 - ]
   • Installation. Refer to INSTALLATION [08/2012 - ]
   TEXT IN ILLUSTRATION
   
   

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

NG → See step   5 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR