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Inspection Procedure 2: The combiner does not work, open or close normally even if combiner open/close switch is operated.
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
COMMENTS ON TROUBLE SYMPTOM
If the combiner does not work, open or close normally even if the combiner open/close switch is operated, there may be some malfunction in the HUD or in the HUD switch.
 
 
PROBABLE CAUSES
  • Malfunction of the HUD switch (Combiner open/close switch: Stuck in OFF)
  • HUD malfunction
    • Open/close judgment switch: Stuck in OFF
    • Motor fails
    • Movable part of the combiner: Jammed by foreign objects, distortion
    • Combiner bearing section: Dust adhesion
  • Damaged harness wires and connectors
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), check special function.
By using the special function of the HUD, check whether the combiner can be opened/closed.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the Scan Tool (M.U.T.-IIISE) ."
(2) Turn the ignition switch to the "ON" position.
Operation check
  • Item 1: Combiner Open (Refer to ).
  • Item 2: Combiner Close (Refer to ).
OK: The combiner is opened/closed normally.
Is the check result normal?
Go to Step 3.
Go to Step 2.
 
STEP 2. Combiner visual inspection
cautionSince the internal mechanism of the HUD is damaged, do not close the combiner manually. (It is automatically stored with turning the ignition switch ON.)
If the combiner does not open, turn OFF the ignition switch to open the combiner slowly by hand, and check that no foreign object is caught around the combiner, and that there is no dust etc. adhering to the bearing section.
Is the check result normal?
Go to Step 6.
Remove foreign objects and dust.
 
STEP 3. Resistance measurement at HUD connector (O/C, SW- terminal).
(1) Disconnect the HUD and HUD switch connector, and measure at the wiring harness side.
(2) Measure the resistance between the HUD connector (O/C) and HUD switch connector terminal No. 8
OK: The resistance should be 2 ohms or less
(3) Measure the resistance between the HUD connector (SW-) and HUD switch connector terminal No. 11
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 4.
Correct the circuit between the HUD connector and HUD switch connector (O/C or SW - terminal).
 
STEP 4. Check the HUD switch.
Check the continuity at the HUD switch (between terminals No. 8 and 11).Refer to .
Is the check result normal?
Go to Step 5.
Replace the HUD switch.
 
STEP 5. Using scan tool (M.U.T.-IIISE), check data list.
Check the input signal of the combiner open/close switch by using the service data of the HUD.
  • When the combiner open/close switch is operated.
 
Item No.Item nameNormal condition
1HUD SWON
Item No.Item nameNormal condition
1HUD SWON
  • When the combiner open/close switch is not operated.
 
Item No.Item nameNormal condition
1HUD SWOFF
Item No.Item nameNormal condition
1HUD SWOFF
OK: Normal conditions are displayed for all the items.
Is the check result normal?
Go to Step 6.
Replace the HUD.
 
STEP 6. Retest the system
Check whether the combiner works normally by operating the combiner open/close switch.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the HUD.