Seat Illumination Circuit: Procedure

HINT: 

The personal lights and seat illumination share the same power source circuit. Therefore, if none of them come on, inspect the power source circuit first.

1. Push the personal light switches.
2. Check that the personal lights come on.

   OK

   Personal lights come on.

NG → See step   7 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Body No. 3 / Active Test.
5. Check the operation.
   BODY NO. 3 (MAIN BODY ECU LH):
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Interior Light (Dim) Operation	Front and rear seat illumination ON / OFF	ON / OFF	-

   OK

   Front and rear seat illumination comes on.

   Result

   Result	Proceed to
   Front seat illumination does not come on	A
   Rear seat illumination does not come on	B
   Neither front nor rear seat illumination comes on	C
   OK	D

   HINT: 

   If the rear seat illumination comes on normally, but the front seat illumination does not come on, there is an open circuit in the overhead J/B.

C → See step   5 

B → See step   3 

A → REPLACE OVERHEAD J/B 

D → PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

1. Remove the rear dome light assembly.
   Fig 1: Identifying Rear Dome Light Assembly Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the (+) lead from the battery to terminal 2 and the (-) lead to terminal 5, and then check that the seat illumination comes on.

   OK

   Seat illumination comes on.

NG → REPLACE REAR DOME LIGHT ASSEMBLY 

OK: Go to next step 

1. Disconnect the R8 rear dome light assembly connector.
   Fig 2: Identifying R5 Overhead J/B Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the R5 overhead J/B connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   R8-2 (ILLB) - R5-4 (ILLB)	Always	Below 1 Ω
   R8-5 (LILL)- R5-32 (LILL)	Always	Below 1 Ω
   R8-2 (ILLB) - Body ground	Always	10 kΩ or higher
   R8-5 (LILL) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE OVERHEAD J/B 

1. Disconnect the Q3 main body ECU LH connector.
   Fig 3: Identifying Q3 Main Body ECU LH Connector

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

   Standard voltage

   Tester Connection	Condition	Specified Condition
   Q3-3 (LGCY) - Body ground	Always	10 to 14 V

NG → See step   6 

OK → REPLACE MAIN BODY ECU LH (COWL SIDE J/B LH) 

1. Disconnect the Q3 main body ECU LH connector.
   Fig 4: Identifying Q3 Main Body ECU LH Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the R5 overhead J/B connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   Q3-3 (LGCY) - R5-12 (CTY)	Always	Below 1 Ω
   Q3-3 (LGCY) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE OVERHEAD J/B 

1. Disconnect the R5 overhead J/B connector.
   Fig 5: Identifying R5 Overhead J/B Connector

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

   Standard voltage

   Tester Connection	Condition	Specified Condition
   R5-1 (+B1) - Body ground	Always	10 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE OVERHEAD J/B