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Home >> Toyota >> 2013 >> Prius Two >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 137 (Lighting System (Diagnostic Codes & Circuit Tests) (Plug-In)) >> Lighting System >> Circuit Tests >> Back-up Light Circuit >> Procedure
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Back-up Light Circuit: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - P/I 2 FUSE AND BODY GROUND) 
    1. Disconnect the 1H No. 1 integration relay connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connector Condition Specified Condition
      1H-7 (BATT) - Body ground Always 11 to 14 V
    3. Disconnect the 1G No. 1 integration relay connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1G-22 (GND1) - Body ground Always Below 1 Ω
      1H-3 (GND2) - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  2. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the A85 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
      1G-13 (BKUP) - A85-15 (BL) Always Below 1 Ω
      1G-13 (BKUP) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - REAR COMBINATION LIGHT ASSEMBLY) 
    1. Disconnect the 1G No. 1 integration relay connector.
    2. Disconnect the R17 or S18 rear combination light assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1G-3 (BCK1) - R17-4 (B) Always Below 1 Ω
      1G-3 (BCK1) - S18-4 (B) Always Below 1 Ω
      1G-3 (BCK1) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. CHECK NO. 1 INTEGRATION RELAY 
    1. Replace the No. 1 integration relay with a new or known good one. Refer to REMOVAL .
    2. Check that the back-up lights operate normally.

      OK

      The back-up lights operate normally.

    NG → See step   5 

    OK → END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE) 

  5. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
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