METER / GAUGE SYSTEM Headup Display Malfunction

DESCRIPTION

The headup display system displays some vehicle information on the windshield glass.

The headup display system consists of the combination mirror meter ECU and combination meter sub-assembly.

The combination mirror meter ECU receives information from the combination meter sub-assembly via communication and projects it on the windshield.

WIRING DIAGRAM

B005ZAGE04

CAUTION / NOTICE / HINT

Tech Tips

Before starting the following inspection, confirm the headup display position and illuminance, then perform the on-vehicle inspection Click here.

PROCEDURE


  1. SYSTEM CHECK


    1. Check the symptom of the headup display.

      Result
      Result Proceed to
      Headup display does not display at all. A
      Display of the headup display is abnormal. B

    B

    SYSTEM CHECK Click here

    A

  2. CHECK HARNESS AND CONNECTOR (COMBINATION METER MIRROR ECU - BODY GROUND)


    1. B005XIME02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Combination Meter Mirror ECU)

      Disconnect the L160 combination meter mirror ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L160-1 (12V) - Body ground Power switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L160-8 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (COMBINATION METER MIRROR ECU - HEADUP DISPLAY SWITCH ASSEMBLY)


    1. Disconnect the L147 headup display switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L160-14 (HUDU) - L147-3 (NVM) Always Below 1 Ω
      L160-14 (HUDU) - Body ground Always 10 kΩ or higher
      L160-15 (HUDO) - L147-4 (CH) Always Below 1 Ω
      L160-15 (HUDO) - Body ground Always 10 kΩ or higher
      L160-16 (E) - L147-1 (E) Always Below 1 Ω
      L160-16 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT HEADUP DISPLAY SWITCH ASSEMBLY


    1. B005ZMRE02
      Text in Illustration
      *a

      Component without harness connected

      (Headup Display Switch Assembly)

      Disconnect the L147 headup display switch assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      3 (NVM) - 1 (E) SET switch is pressed 1782 to 1818 Ω
      SET switch is not pressed 10 kΩ or higher
      HUD tilt up switch is pressed 811.8 to 828.2 Ω
      HUD tilt up switch is not pressed 10 kΩ or higher
      HUD tilt down switch is pressed 326.7 to 333.3 Ω
      HUD tilt down switch is not pressed 10 kΩ or higher
      4 (CH) - 1 (E) HUD main switch is pressed 1782 to 1818 Ω
      HUD main switch is not pressed 10 kΩ or higher
      HUD rheostat up switch is pressed 811.8 to 828.2 Ω
      HUD rheostat up switch is not pressed 10 kΩ or higher
      HUD rheostat down switch is pressed 326.7 to 333.3 Ω
      HUD rheostat down switch is not pressed 10 kΩ or higher

    OK

    REPLACE COMBINATION METER MIRROR ECU Click here

    NG

    REPLACE HEADUP DISPLAY SWITCH ASSEMBLY Click here

  5. SYSTEM CHECK


    1. Check the symptom of the headup display.

      Result
      Result Proceed to
      All display items are abnormal. A
      Vehicle speed display is abnormal.
      Dynamic radar cruise control display is abnormal.
      Pre crash safety system display is abnormal.
      Touch tracer display is abnormal.
      Turn-by-turn navigation display is abnormal. B

    B

    CHECK HARNESS AND CONNECTOR (COMBINATION METER SUB-ASSEMBLY - COMBINATION METER MIRROR ECU) Click here

    A

  6. CHECK HARNESS AND CONNECTOR (COMBINATION METER SUB-ASSEMBLY - COMBINATION METER MIRROR ECU)


    1. Disconnect the L141 combination meter sub-assembly connector.

    2. Disconnect the L160 combination meter mirror ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L141-7 (TX+) - L160-3 (SIH) Always Below 1 Ω
      L141-7 (TX+) - Body ground Always 10 kΩ or higher
      L141-8 (TX-) - L160-4 (SIL) Always Below 1 Ω
      L141-8 (TX-) - Body ground Always 10 kΩ or higher
      L141-9 (SIH) - L160-5 (TX+) Always Below 1 Ω
      L141-9 (SIH) - Body ground Always 10 kΩ or higher
      L141-10 (SIL) - L160-6 (TX-) Always Below 1 Ω
      L141-10 (SIL) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. REPLACE COMBINATION METER MIRROR ECU


    1. Replace the combination meter mirror ECU with a new or a known good one Click here.

      OK
      The operation of the headup display returns to normal.
      Result
      Result Proceed to
      OK A
      NG (w/o Multi-information display) B
      NG (w/ Multi-information display) C

    OK

    END

    B

    REPLACE METER CIRCUIT PLATE Click here

    C

    REPLACE COMBINATION METER SUB-ASSEMBLY Click here

  8. CHECK HARNESS AND CONNECTOR (COMBINATION METER SUB-ASSEMBLY - COMBINATION METER MIRROR ECU)


    1. Disconnect the L141 combination meter sub-assembly connector.

    2. Disconnect the L160 combination meter mirror ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L141-7 (TX+) - L160-3 (SIH) Always Below 1 Ω
      L141-7 (TX+) - Body ground Always 10 kΩ or higher
      L141-8 (TX-) - L160-4 (SIL) Always Below 1 Ω
      L141-8 (TX-) - Body ground Always 10 kΩ or higher
      L141-9 (SIH) - L160-5 (TX+) Always Below 1 Ω
      L141-9 (SIH) - Body ground Always 10 kΩ or higher
      L141-10 (SIL) - L160-6 (TX-) Always Below 1 Ω
      L141-10 (SIL) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. REPLACE COMBINATION METER MIRROR ECU


    1. Replace the combination meter mirror ECU with a new or a known good one Click here.

      OK
      The operation of the headup display returns to normal.
      Result
      Result Proceed to
      OK A
      NG (w/o Multi-information display) B
      NG (w/ Multi-information display) C

    A

    END

    C

    REPLACE COMBINATION METER SUB-ASSEMBLY Click here

    B

  10. REPLACE METER CIRCUIT PLATE


    1. Replace the meter circuit plate with a new or a known good one Click here.

      OK
      The operation of the headup display returns to normal.

    OK

    END

    NG

    REPLACE NAVIGATION RECEIVER ASSEMBLY Click here

  11. REPLACE COMBINATION METER SUB-ASSEMBLY


    1. Replace the combination meter sub-assembly with a new or a known good one Click here.

      OK
      The operation of the headup display returns to normal.

    OK

    END

    NG

    REPLACE NAVIGATION RECEIVER ASSEMBLY Click here