Inspection Procedure 6: Icy Road Surface Warning Function does not Work Normally.




CIRCUIT OPERATION


If the ambient temperature of RV meter becomes 3°C or lower when the ignition switch is turned ON, the freeze mark flashes for 10 seconds on the RV meter and the ETACS-ECU buzzer sounds at the same time.
note Once the icy road surface warning is given, if the ambient temperature drops to 3°C or lower after the ambient temperature rises to 6°C or higher, the freeze mark of RV meter only flashes for 10 seconds. Also, once the ambient temperature rises to 4 to 5°C after an icy road surface warning is given, when the temperature drops to 3°C or lower again, the icy road surface warning is not given.

COMMENTS ON TROUBLE SYMPTOM


When other indications are normal, the malfunction of RV meter or ETACS-ECU is considered.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T-III to diagnose the CAN bus lines.

Q. Is the check result satisfactory?
Go to Step 2
Repair the CAN bus lines (Refer to GROUP 54C, Diagnosis - Can Bus Diagnostics Table ). After diagnosing the CAN bus lines, go to Step 2.

STEP 2. M.U.T-III other system diagnosis code.
Check that the ETACS-ECU does not set the diagnosis code.

Q. Is the diagnosis code set?
Diagnose ETACS-ECU (Refer to GROUP 54A, Diagnosis - diagnosis code chart ).
Go to Step 3.

STEP 3. M.U.T.-III diagnosis code.
When the ignition switch is turned to the "LOCK" (OFF) position, check that the CAN adapter does not set the diagnosis code.

Q. Is the diagnosis code set?
Refer to diagnosis code chart .
Go to Step 4.

Step 4. Recheck for malfunction.

Q. Is a malfunction eliminated?
If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .
Replace the RV meter.