LIGHTING SYSTEM Back-up Light Circuit

DESCRIPTION

The power management control ECU controls the back-up lights via the engine room junction block assembly.

CAUTION / NOTICE / HINT

PROCEDURE

1. Click here

   CHECK DTC OUTPUT (HYBRID CONTROL SYSTEM)

   
   

   1. Check for DTCs (Click here).

      OK
      Hybrid Control System DTCs are not output.

   
   
   • OKClick here
   • NG

     GO TO HYBRID CONTROL SYSTEM (Click here)

2. Click here

   CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY

   
   

   1. Using a voltmeter, check the signal reading of the engine room junction block assembly (Click here).

      OK
      Output signal reading is normal.

   
   
   • OKClick here
   • NG

     INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (RESULTS OF SIGNAL READING CHECK) (Click here)

3. Click here

   CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY POWER SOURCE AND BODY GROUND)

   
   
   1. 

      Remove the engine room junction block assembly from the engine room relay block and junction block assembly (Click here).

      Table 1. Text in Illustration

      *a

      Component without engine room junction block assembly connected (Engine Room Relay Block and Junction Block Assembly)

      -

      -

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

      Standard Voltage
      Tester Connection Condition Specified Condition A-1 (BATT) - Body ground Power switch off 11 to 14 V B-1 (ALT) - Body ground Power switch off 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1F-3 (GND1) - Body ground Always Below 1 Ω 1G-4 (GND2) - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

4. Click here

   CHECK HARNESS AND CONNECTOR (REAR LIGHT ASSEMBLY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

   
   

   1. Disconnect the U7 rear light assembly LH connector.

   2. Disconnect the U1 rear light assembly RH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1M-1 (BKLP) - U7-1 (B/U) Always Below 1 Ω 1M-1 (BKLP) - U1-1 (B/U) Always Below 1 Ω

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

5. Click here

   CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

   
   

   1. Disconnect the A31 power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1F-9 (BLPS) - A31-15 (BL) Always Below 1 Ω 1F-9 (BLPS) - Body ground Always 10 kΩ or higher

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

6. Click here

   CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY

   
   

   1. Replace the engine room junction block assembly with a new or known good one (Click here).

      OK
      The back-up lights operate normally.

   
   
   • OK

     END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)

   • NG

     REPLACE POWER MANAGEMENT CONTROL ECU (Click here)