LIGHTING SYSTEM Taillight Relay Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) receives headlight dimmer switch information signals, and illuminates the clearance lights, taillights and license plate lights.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (TAILLIGHT RELAY)

   
   

   1. Using the intelligent tester, perform the Active Test Click here.

      Main Body

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

      OK
      Taillight relay operates (taillights illuminate).

      Result
      Result Proceed to NG A OK B

   
   

   B

   REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

   A

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

   
   

   1. Disconnect the 3E*1 or 3F*2 instrument panel junction block assembly connector.

      
      

      • *1: for LHD

      • *2: for RHD

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition 3E-1 - Body ground Always 11 to 14 V
      for RHD
      Tester Connection Condition Specified Condition 3F-1 - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   
   

   1. Remove the instrument panel junction block assembly Click here.

   2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

      

      Text in Illustration

      *A	for LHD	*B	for RHD
      *a	Component without harness connected (Instrument Panel Junction Block Assembly)	-	-

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition 3E-1 - 3C-2 Always 10 kΩ or higher 3E-1 - 3D-10 Always 10 kΩ or higher 3C-2 - 3D-10 Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition 3F-1 - 3C-2 Always 10 kΩ or higher 3F-1 - 3D-10 Always 10 kΩ or higher 3C-2 - 3D-10 Always Below 1 Ω

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition 3C-2 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3E-1 Connect a negative (-) lead from the battery → MB-14 (TRLY) 11 to 14 V Not connect a positive (+) lead from the battery → 3E-1 Not connect a negative (-) lead from the battery → MB-14 (TRLY) Below 1 V 3D-10 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3E-1 Connect a negative (-) lead from the battery → MB-14 (TRLY) 11 to 14 V Not connect a positive (+) lead from the battery → 3E-1 Not connect a negative (-) lead from the battery → MB-14 (TRLY) Below 1 V
      for RHD
      Tester Connection Condition Specified Condition 3C-2 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3F-1 Connect a negative (-) lead from the battery → MB-14 (TRLY) 11 to 14 V Not connect a positive (+) lead from the battery → 3F-1 Not connect a negative (-) lead from the battery → MB-14 (TRLY) Below 1 V 3D-10 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3F-1 Connect a negative (-) lead from the battery → MB-14 (TRLY) 11 to 14 V Not connect a positive (+) lead from the battery → 3F-1 Not connect a negative (-) lead from the battery → MB-14 (TRLY) Below 1 V

   
   

   OK

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   NG

   REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here