Inspection Procedure 14
Inspection Procedure 14: The dome light, the turn-signal lights and the horn do not operate through the answer back function.
CAUTION:
Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
OPERATION
When the keyless entry function is used, the keyless entry hazard answer back function, dome light or horn answer back function operate as set by ETACS customization function. (If the flashing count is set to 0 with a customization function, no answer back function is performed.).
If the theft alarm is defective, the keyless entry hazard answer back function may not operate normally.
PROBABLE CAUSES
- Function setting error or no setting with a customization
- Malfunction of the turn signal light
- Malfunction of the dome light
- Malfunction of the horn
- Malfunction of the theft alarm sensor
- Malfunction of the theft alarm siren
- Malfunction of ETACS-ECU
DIAGNOSTIC PROCEDURE
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
STEP 1. Verify the hazard warning lights.
Check that the hazard warning lights illuminate normally.
Q. Is the check result normal?
YES Go to Step 2.
NO Inspection Procedure 1.
STEP 2. Verify the dome light.
Check that the dome light illuminate normally.
Q. Is the check result normal?
YES Go to Step 3.
NO Symptom Chart.
STEP 3. Verify the horn.
Check that the horn normally.
Q. Is the check result normal?
YES Go to Step 4.
NO Replace the horn Service and Repair).
STEP 4. Check the customize function.
Check that any one of the followings other than "Lock: 0, Unlock: 0" is set for "Hazard answer back" with a customization function.
- Lock:1, Unlock:2
- Lock:1, Unlock:0
- Lock:0, Unlock:2
- Lock:2, Unlock:1
- Lock:2, Unlock:0
- Lock:0, Unlock:1
Q. Is the check result normal?
YES Go to Step 5.
NO Set "Hazard answer back" to any one other than "Lock: 0, Unlock: 0" with a customization function (Refer to Programming and Relearning).
STEP 5. Check the customize function.
Check that any one of the followings other than "Not sound horn" is set for "Horn chirp by RKE" with a customization function.
- Lock any time
- W lock any time
Q. Is the check result normal?
YES Go to Step 6.
NO Set "Horn chirp by RKE" to any one other than "Not sound horn" with a customization function (Refer to Configuration Function).
STEP 6. Using scan tool MB991958, read the diagnostic trouble code.
(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."
(2)Turn the ignition switch to the "ON" position.
(3)Check whether the theft alarm related DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Diagnose the theft alarm. Refer to Antitheft and Alarm Systems.
NO Go to Step 7.
STEP 7. Using scan tool MB991958, read the diagnostic trouble code.
(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."
(2)Turn the ignition switch to the "ON" position.
(3)Check whether the KOS-ECU related DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Diagnose the KOS-ECU. Refer to Keyless Operation System (KOS).
NO Go to Step 8.
STEP 8. Check of the troubles
Check if the keyless entry hazard answer back, doom light answer back and horn answer back function works normally.
Q. Is the check result normal?
YES Intermittent malfunction How to Cope With Intermittent Malfunctions.)
NO Replace ETACS-ECU.