METER / GAUGE SYSTEM Headup Display Malfunction

DESCRIPTION

This circuit is the power source circuit for the headup display (combination meter mirror ECU). This circuit provides two types of power sources; one is a constant power source, and the other is a IG power source.

WIRING DIAGRAM

A01JAHIE04

INSPECTION PROCEDURE

Tech Tips

Before starting the following inspection, confirm the headup display (combination meter mirror ECU) position and illuminance, then perform the on-vehicle inspection Click here.

PROCEDURE


  1. SYSTEM CHECK


    1. Check the symptom of the headup display (combination meter mirror ECU).

      Result
      Result Proceed to
      Headup display (combination meter mirror ECU) does not operate at all. A
      Cruise information display does not change. B

    B

    READ VALUE USING INTELLIGENT TESTER Click here

    A

  2. CHECK HARNESS AND CONNECTOR (HEADUP DISPLAY CIRCUIT)


    1. A01JC7VE32
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Headup Display (Combination Meter Mirror ECU))

      Disconnect the L111 connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L111-13 (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
      L111-16 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HEADUP DISPLAY (COMBINATION METER MIRROR ECU) Click here

  3. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent tester ON.

    4. Enter the following menus: Body / Combination Meter / Data List.

    5. Check the values by referring to the table below.

      Combination Meter
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Head Up Display Switch (Up) Headup display position up switch condition OFF: Headup display position up switch not pressed -
      ON: Headup display position up switch pressed -
      Head Up Display Switch (Down) Headup display position down switch condition OFF: Headup display position down switch not pressed -
      ON: Headup display position down switch pressed -
      Head Up Display Switch (Main) Headup display main switch condition OFF: Headup display main switch not pressed -
      ON: Headup display main switch pressed -
      OK
      Each switch condition displayed on the intelligent tester changes with the actual switch operation.

    B

    CHECK HARNESS AND CONNECTOR (HEADUP DISPLAY - NO. 3 METER CIRCUIT PLATE) Click here

    A

    REPLACE COMBINATION METER ASSEMBLY (NO. 3 METER CIRCUIT PLATE) Click here

  4. CHECK HARNESS AND CONNECTOR (HEADUP DISPLAY - NO. 3 METER CIRCUIT PLATE)


    1. Disconnect the L111 and L57 connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L111-17 (BKR) - L106-5 (BKR) Always Below 1 Ω
      L111-17 (BKR) - Body ground Always 10 kΩ or higher
      L111-18 (LAT) - L106-6 (LAT) Always Below 1 Ω
      L111-18 (LAT) - Body ground Always 10 kΩ or higher
      L111-19 (CLKH) - L106-7 (CLKH) Always Below 1 Ω
      L111-19 (CLKH) - Body ground Always 10 kΩ or higher
      L111-20 (CLKL) - L106-8 (CLKL) Always Below 1 Ω
      L111-20 (CLKL) - Body ground Always 10 kΩ or higher
      L111-21 (SIH) - L106-9 (SIH) Always Below 1 Ω
      L111-21 (SIH) - Body ground Always 10 kΩ or higher
      L111-22 (SIL) - L106-10 (SIL) Always Below 1 Ω
      L111-22 (SIL) - Body ground Always 10 kΩ or higher
      L111-23 (WE) - L106-11 (WE) Always Below 1 Ω
      L111-23 (WE) - Body ground Always 10 kΩ or higher
      L111-2 (STP1) - L106-14 (STP1) Always Below 1 Ω
      L111-2 (STP1) - Body ground Always 10 kΩ or higher
      L111-3 (STP2) - L106-15 (STP2) Always Below 1 Ω
      L111-3 (STP2) - Body ground Always 10 kΩ or higher
      L111-4 (STP3) - L106-16 (STP3) Always Below 1 Ω
      L111-4 (STP3) - Body ground Always 10 kΩ or higher
      L111-5 (STP4) - L106-17 (STP4) Always Below 1 Ω
      L111-5 (STP4) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT TRIP SWITCH


    1. A01JAZZE02
      Text in Illustration
      *1

      Component without harness connected

      (Trip Switch)

      Disconnect the L57 connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      2 (CH) - 12 (E) HUD/MODE switch pressed Below 1 Ω
      2 (CH) - 12 (E) Always 10 kΩ or higher
      12 (E) - 14 (HDD) Down switch pressed Below 1 Ω
      12 (E) - 14 (HDD) Always 10 kΩ or higher
      12 (E) - 15 (HDU) Up switch pressed Below 1 Ω
      12 (E) - 15 (HDU) Always 10 kΩ or higher

    NG

    REPLACE TRIP SWITCH Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (TRIP SWITCH - NO. 3 METER CIRCUIT PLATE)


    1. Disconnect the L27, L57, and L107 connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L57-1 (CS) - L27-2 (TC O) Always Below 1 Ω
      L57-1 (CS) - Body ground Always 10 kΩ or higher
      L57-9 (HOUR) - L27-12 (HOUR) Always Below 1 Ω
      L57-9 (HOUR) - Body ground Always 10 kΩ or higher
      L57-10 (MIN) - L27-13 (MIN) Always Below 1 Ω
      L57-10 (HOUR) - Body ground Always 10 kΩ or higher
      L57-11 (RST) - L27-17 (RST) Always Below 1 Ω
      L57-11 (RST) - Body ground Always 10 kΩ or higher
      L57-12 (E) - L107-2 (E) Always Below 1 Ω
      L57-12 (E) - Body ground Always 10 kΩ or higher
      L57-15 (HDU) - L107-7 (HDS) Always Below 1 Ω
      L57-15 (HDU) - Body ground Always 10 kΩ or higher
      L57-14 (HDD) - L107-4 (HUDD) Always Below 1 Ω
      L57-14 (HDD) - Body ground Always 10 kΩ or higher
      L57-3 (TAIL) - L107-3 (HUDI) Always Below 1 Ω
      L57-3 (TAIL) - Body ground Always 10 kΩ or higher
      L57-2 (CH) - L107-8 (HUDO) Always Below 1 Ω
      L57-2 (CH) - Body ground Always 10 kΩ or higher
      L57-6 (NVI) - L107-9 (IIND) Always Below 1 Ω
      L57-6 (NVI) - Body ground Always 10 kΩ or higher
      L57-7 (NVM) - L107-1 (NVSW) Always Below 1 Ω
      L57-7 (NVM) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. REPLACE HEADUP DISPLAY (COMBINATION METER MIRROR ECU)


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

      OK
      The operation of the headup display (combination meter mirror ECU) returns to normal.

    NG

    REPLACE COMBINATION METER ASSEMBLY (NO. 3 METER CIRCUIT PLATE) Click here

    OK

    END