Illumination Circuit: Procedure

1. Check if the illumination for the integration control and panel assembly, steering pad switch, glove box light, cigarette lighter, or others (seat heater switch, front seat memory 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.	A
   Illumination comes on for all components except radio receiver.	B
   Illumination comes on for all components except integration control and panel assembly.	C
   No illumination comes on for radio receiver, integration control and panel assembly, glove box light, front seat memory switch, cigarette lighter, etc.)	D

D → See step   7 

C → See step   6 

B → See step   5 

A: Go to next step 

1. Disconnect the L134 spiral cable sub-assembly connector.
   Fig 1: Identifying L134 Spiral Cable Sub-Assembly & L10 No. 1 Meter ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the L10 No. 1 meter ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   L134-14 (ILL-) - L10-16 (ILL-)	Always	Below 1 Ω
   L134-14 (ILL-) - Body ground	Always	10 kΩ or higher
   L134-7 (+B) - A69-1 (CUTD)	Always	Below 1 Ω
   L134-7 (+B) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the steering pad switch assembly. Refer to REMOVAL .
   Fig 2: Identifying Steering Pad Switch Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the positive (+) lead to terminal 2 (ILL+-1) and the negative (-) lead to terminal 5 (ILL--1) of the steering pad switch connector.
3. Check if the illumination for the steering pad switch comes on.

   OK

   Illumination for the steering pad switch comes on.

NG → See step   8 

OK: Go to next step 

1. Remove the spiral cable sub-assembly. Refer to REMOVAL .
   Fig 3: Identifying Spiral Cable Sub-Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Spiral Cable Position	Specified Condition
   14 (ILL-) - 6 (ILL-)	2.5 rotations to the left	Below 3 Ω
   	Center
   	2.5 rotations to the right
   7 (+B) - 12 (+B)	2.5 rotations to the left	Below 3 Ω
   	Center
   	2.5 rotations to the right

   NOTE:

   The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may prevent the airbag from deploying. Be sure to read the Precaution for the SRS. Refer to PRECAUTION .

NG → See step   9 

OK → See step   10 

1. Disconnect the L51 radio receiver assembly connector.
   Fig 4: Identifying L51 radio receiver assembly & L10 No. 1 meter ECU sub-assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the L10 No. 1 meter ECU sub-assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   L51-12 (ILL-) - L10-16 (ILL-)	Always	Below 1 Ω
   L51-12 (ILL-) - Body ground	Always	10 kΩ or higher

4. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Switch Condition	Specified Condition
   L51-2 (ILL+) - Body ground	Light control system TAIL or HEAD	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   11 

1. Disconnect the L35 integration control and panel assembly connector.
   Fig 5: Identifying L35 integration control and panel assembly & L10 No. 1 meter ECU sub-assembly connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the L10 No. 1 meter ECU sub-assembly connector.
3. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Switch Condition	Specified Condition
   L35-12 (ILL+) - Body ground	Light control switch TAIL or HEAD	11 to 14 V

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

   Standard resistance

   Tester Connection	Condition	Specified Condition
   L35-5 (HILL) - L10-16 (ILL-)	Always	Below 1 Ω
   L35-5 (HILL) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   12