LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2012 >> Matrix Base, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 334 (Smart Key System (Keyless Entry) (Diagnostic Codes & Symptom Tests)) >> SMART KEY SYSTEM (for Start Function) >> System Tests >> Power Source Mode does not Change >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Power Source Mode does not Change: Procedure

WARNING: This page is about a different car, the 2012 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK SMART KEY SYSTEM 
    1. Remove the battery of the electrical key transmitter. Refer to REMOVAL - Step 1 .
      Fig 1: Identifying Distance Between Engine Switch And Key
      GTY200179Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Touch the logo side mark of the key or card key to the engine witch.
    3. Check that the engine switch can be turned on (IG).

      Result

      Result Proceed to
      Power source mode does not change to on (ACC) A
      Power source mode does not change to on (IG) B
      Power source mode does not change to on (IG and ACC) C
      Power source mode is turned on D

    B → See step   6 

    C → See step   14 

    D → See step   18 

    A: Go to next step 

  2. INSPECT ACC RELAY 
    1. Remove the ACC relay from the relay block No. 8.
      Fig 2: Inspecting ST CUT Relay Connector Terminals
      GTY120776Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified condition
      3 - 5 When battery voltage is not applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 When battery voltage is applied to terminals 1 and 2 Below 1 Ω

    NG → REPLACE ACC RELAY 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ACC RELAY) 
    1. Disconnect the E50 connector from the main body ECU (instrument panel junction block).
      Fig 3: Identifying ACC Relay Terminals & E50 Harness Connector
      GTY291099Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      E50-4 (ACCD) - Relay block No. 8 ACC relay terminal 1 Always Below 1 Ω
      E50-4 (ACCD) or Relay block No. 8 ACC relay terminal 1 - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU - ACC RELAY) 

    OK: Go to next step 

  4. INSPECT FUSE (ACC-B FUSE) 
    1. Remove the ACC-B fuse from the main body ECU (instrument panel junction block).
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      ACC-B fuse Always Below 1 Ω

    NG → REPLACE FUSE (ACC-B FUSE) 

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - ACC RELAY) 
    1. Disconnect the 2M connector from the main body ECU (instrument panel junction block)
      Fig 4: Identifying ACC Relay Terminals & 2M Connector
      GTY293378Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2M-9 - Relay block No. 8 ACC relay terminal 3 Always Below 1 Ω
      2M-9 or Relay block No. 8 ACC relay terminal 3 - Body ground Always 10 k Ω or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - ACC RELAY) 

    OK → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK 

  6. INSPECT IG1 RELAY 
    1. Remove the IG1 relay from the main body ECU (instrument panel junction block).
      Fig 5: Inspecting IG1 Relay Of Instrument Panel Junction Block
      GTY191640Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 5 When battery voltage is not applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 When battery voltage is applied to terminals 1 and 2 Below 1 Ω

    NG → REPLACE IG1 RELAY 

    OK: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - INSTRUMENT PANEL JUNCTION BLOCK) 
    1. Disconnect the E51 and 2F connectors from the main body ECU (Instrument panel junction block).
      Fig 6: Identifying E51 And 2F Connectors
      GTY181520Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      E51-6 (IG1D) - 2F-3 Always Below 1 Ω
      E51-6 (IG1D) or 2F-3 - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU - INSTRUMENT PANEL JUNCTION BLOCK) 

    OK: Go to next step 

  8. CHECK HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - BODY GROUND) 
    1. Disconnect the 2E connector from main body ECU (Instrument panel junction block).
      Fig 7: Identifying 2E Connector Of Main Body ECU (Instrument Panel Junction Block)
      GTY200274Courtesy 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
      2E-17 - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - BODY GROUND) 

    OK: Go to next step 

  9. INSPECT FUSE (IG2 FUSE) 
    1. Remove the IG2 fuse from engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      IG2 fuse Always Below 1 Ω

    NG → REPLACE FUSE (IG2 FUSE) 

    OK: Go to next step 

  10. CHECK HARNESS AND CONNECTOR (BATTERY - ENGINE ROOM RELAY BLOCK) 
    1. Disconnect the 1E connector from engine room relay block.
      Fig 8: Identifying Wire Harness & 1E Connector (Engine Room Relay Block)
      GTY293971Courtesy 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
      1E-1 - Body ground Always 11 to 14 V

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ENGINE ROOM RELAY BLOCK) 

    OK: Go to next step 

  11. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ENGINE ROOM RELAY BLOCK) 
    1. Disconnect the E51 connector from the main body ECU (instrument panel junction block).
      Fig 9: Identifying 1A & E51 Connectors
      GTY293558Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the 1A connector from engine room relay block.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      E51-5 (IG2D) - 1A-2 Always Below 1 Ω
      E51-5 (IG2D) or 1A-2 - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU - ENGINE ROOM RELAY BLOCK) 

    OK: Go to next step 

  12. CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK - BODY GROUND) 
    1. Measure the resistance according to the value(s) in the table below.
      Fig 10: Identifying 1A Connector (Engine Room Relay Block)
      GTY291425Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      1A-3 - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK - BODY GROUND) 

    OK: Go to next step 

  13. INSPECT ENGINE ROOM RELAY BLOCK (IG2 RELAY) 
    1. Remove the engine room relay block.
      Fig 11: Inspecting Engine Room Relay Block (IG2 Relay)
      GTY193396Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1E-1 - 1A-4 When battery voltage is not applied to terminals 1A-2 and 1A-3 10 kΩ or higher
      1E-1 - 1A-4 When battery voltage is applied to terminals 1A-2 and 1A-3 Below 1 Ω

    NG → REPLACE ENGINE ROOM RELAY BLOCK 

    OK → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK) 

  14. CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK) 
    1. Disconnect the 2G connector from main body ECU (Instrument panel junction block).
      Fig 12: Identifying Main Body ECU 2G Connector (Instrument Panel Junction Block)
      GTY170850Courtesy 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
      2G-1 - Body ground Always 11 to 14 V

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK) 

    OK: Go to next step 

  15. CHECK HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - BODY GROUND) 
    1. Disconnect the 2E connector from main body ECU (instrument panel junction block).
      Fig 13: Identifying 2E Connector Of Main Body ECU (Instrument Panel Junction Block)
      GTY200275Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2E-17 - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - BODY GROUND) 

    OK: Go to next step 

  16. CHECK HARNESS AND CONNECTOR (BATTERY - MAIN BODY ECU) 
    1. Disconnect the E50 and E51 connectors from the main body ECU (Instrument panel junction block).
      Fig 14: Identifying E50 And E51 Connectors
      GTY187750Courtesy 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
      E50-6 (AM2) - Body ground Always 11 to 14 V
      E51-1 (AM1) - Body ground Always 11 to 14 V

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - MAIN BODY ECU) 

    OK: Go to next step 

  17. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BODY GROUND) 
    1. Disconnect the E51 connector from main body ECU (Instrument panel junction block).
      Fig 15: Identifying E51 Connector Terminals
      GTY200277Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      E51-4 (GND2) - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU - BODY GROUND) 

    OK → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK) 

  18. GO TO SMART KEY SYSTEM (ENTRY FUNCTION). Refer to  Room Oscillator does not Recognize Key 
scientia non olet · About LEMON Manuals