LIGHTING SYSTEM Taillight Relay Circuit

DESCRIPTION

• The main body ECU receives the light control switch TAIL signal to control the taillight relay.

• When the light control switch is in the AUTO position, the main body ECU receives the ambient light level signal from the automatic light control sensor to control the taillight relay.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch on (IG).

   3. Turn the intelligent tester on.

   4. Select the following menu items: Body Electrical / Main Body / Active Test.

   5. Check that the relay operates.

      Main Body:

      Tester Display	Test Part	Control Range	Diagnostic Note
      Taillight Relay	Taillight relay	ON/OFF	-

      OK
      Taillight relay operates. (Taillights illuminate.)

   
   

   NG

   INSPECT FUSE (TAIL) Click here

   OK

   PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

2. INSPECT FUSE (TAIL)

   
   

   1. Remove the TAIL fuse from the instrument panel junction block.

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

      Standard resistance
      Tester Connection Condition Specified Condition TAIL fuse Always Below 1 Ω

   
   

   NG

   REPLACE FUSE

   OK

3. INSPECT TAILLIGHT RELAY (TAIL)

   
   

   1. 

      Remove the taillight relay from the instrument panel junction block.

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

      Standard resistance
      Tester Connection Condition Specified Condition 3 - 5 Voltage is not applied between terminals 1 and 2 10 kΩ or higher Apply the battery voltage between terminals 1 and 2 Below 1 Ω 3 - 4 Voltage is not applied between terminals 1 and 2 Below 1 Ω Apply the battery voltage between terminals 1 and 2 10 kΩ or higher

   
   

   NG

   REPLACE TAILLIGHT RELAY

   OK

4. INSPECT MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)

   
   

   1. 

      Measure the voltage between the loading slot of the TAIL fuse and body ground.

      Standard voltage
      Tester Connection Condition Specified Condition TAIL fuse terminal - Body ground Light control switch OFF → TAIL Below 1 V → 11 to 14 V

   
   

   NG

   CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK) Click here

   OK

   REPAIR OR REPLACE HARNESS OR CONNECTOR (FUSE - BODY GROUND)

5. CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK)

   
   

   1. 

      Disconnect the 1A instrument panel junction block connector.

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

      Standard voltage
      Tester Connection Condition Specified Condition 1A-1 - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)