Headup Display Malfunction: Procedure

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 → See step   5 

A: Go to next step 

1. Disconnect the F118 connector.
   Fig 1: Identifying Headup Display Connector Terminal (Combination Meter Mirror ECU)

   Courtesy 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
   F118-1 (IG) - Body ground	Power switch on (IG)	11 to 14 V
   F118-2 (B) - Body ground	Power switch off	11 to 14 V
   F118-3 (ACC) - Body ground	Power switch on (ACC)	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F118-5 (ES) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Headup Display (Combination Meter Mirror ECU))

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the F117 and F118 connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F118-12 (HUD1) - F117-6 (TAIL)	Always	Below 1 Ω
   F118-12 (HUD1) - Body ground	Always	10 kΩ or higher
   F118-13 (NAVI) - F117-2 (NVI)	Always	Below 1 Ω
   F118-13 (NAVI) - Body ground	Always	10 kΩ or higher
   F118-14 (SW1) - F117-1 (NVM)	Always	Below 1 Ω
   F118-14 (SW1) - Body ground	Always	10 kΩ or higher
   F118-15 (SW2) - F117-7 (CH)	Always	Below 1 Ω
   F118-15 (SW2) - Body ground	Always	10 kΩ or higher
   F118-16 (E) - F117-4 (E)	Always	Below 1 Ω
   F118-16 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the F117 connector.
   Fig 2: Identifying Headup Display Switch Assembly Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   1 (NVM) - 4 (E)	NAVI main switch is pressed	1782 to 1818 Ω
   	NAVI main switch is not pressed	10 kΩ or higher
   	HUD position up switch is pressed	811.8 to 828.2 Ω
   	HUD position up switch is not pressed	10 kΩ or higher
   	HUD position down switch is pressed	326.7 to 333.3 Ω
   	HUD position down switch is not pressed	10 kΩ or higher
   7 (CH) - 4 (E)	HUD main switch is pressed	1782 to 1818 Ω
   	HUD main switch is not pressed	10 kΩ or higher
   	HUD contrast up switch is pressed	811.8 to 828.2 Ω
   	HUD contrast up switch is not pressed	10 kΩ or higher
   	HUD contrast down switch is pressed	326.7 to 333.3 Ω
   	HUD contrast down switch is not pressed	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1	Component without harness connected (Headup Display Switch Assembly)

NG → See step   14 

OK → See step   15 

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

   Result

   Result	Proceed to
   All the display is malfunctioning.	A
   Vehicle speed display is malfunctioning.
   Dynamic radar cruise control display is malfunctioning.
   Pre-collision system display is malfunctioning.
   Navigation system display is malfunctioning.	B

B → See step   9 

A: Go to next step 

1. Check for DTCs. Refer to ON-VEHICLE INSPECTION .

   Result

   Result	Proceed to
   DTC is output.	A
   DTC is not output.	B

B → See step   8 

A: Go to next step 

1. Disconnect the F4 and F118 connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F4-19 (TX+) - F118-6 (TX-)	Always	Below 1 Ω
   F4-19 (TX+) - Body ground	Always	10 kΩ or higher
   F4-20 (CS) - F118-8 (CS)	Always	Below 1 Ω
   F4-20 (CS) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the headup display (combination meter mirror ECU) with a new or a known good one. Refer to REMOVAL .

   OK

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

NG → See step   13 

OK → END 

1. Check for DTCs. Refer to ON-VEHICLE INSPECTION .

   Result

   Result	Proceed to
   DTC is output.	A
   DTC is not output.	B

B → See step   11 

A: Go to next step 

1. Disconnect the F4 and F118 connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F4-19 (TX+) - F118-6 (TX-)	Always	Below 1 Ω
   F4-19 (TX+) - Body ground	Always	10 kΩ or higher
   F4-20 (CS) - F118-8 (CS)	Always	Below 1 Ω
   F4-20 (CS) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the combination meter assembly with a new or a known good one. Refer to REMOVAL .

   OK

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

NG → See step   12 

OK → END 

1. Replace the headup display (combination meter mirror ECU) with a new or a known good one. Refer to REMOVAL .

   OK

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

NG → See step   16 

OK → END