Inspection Procedure 15

Inspection Procedure 15: 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.)

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 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 : Refer to Chassis Electrical, Inspection Procedure 1: The Hazard Warning lights does not Illuminate.

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 : Refer to Chassis Electrical, Trouble 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 (Refer to Chassis Electrical, Horn).

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.

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.

STEP 6. Using scan tool MB991958, read the diagnostic trouble code.

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.






1. Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III)." How To Connect The Scan Tool (M.U.T.-III)
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. Diagnostic Trouble Code Descriptions

NO : Go to Step 7.

STEP 7. 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 (Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.)

NO : Replace ETACS-ECU.