Inspection Procedure E-2
Keyless Entry System: The Dome Light, the Turn-signal Lights and the Horn do not Operate Through the Answerback Function.CIRCUIT OPERATION
The ETACS-ECU operates the following functions when it receives lock or unlock signal from the transmitter:
- Dome light answerback function
- Hazard warning lights answerback function
- Horn answerback function
TECHNICAL DESCRIPTION (COMMENT)
The hazard warning lights and horn answerback functions can be disabled or enabled. (These functions can be disabled). However, the dome light answerback function can not be disabled.
TROUBLESHOOTING HINTS
- Malfunction of the hazard warning lights
- Malfunction of the theft-alarm horn
- Malfunction of the horn
- Malfunction of the dome light
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Test Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface
- MB991827: MUT-III USB cable
- MB991911: MUT-III Main harness B
STEP 1. Check the keyless entry system.
Q: Does the keyless entry system work normally?
YES: Go to Step 2.
NO: Refer to Inspection Procedure E-1 "Keyless entry system does not work."
STEP 2. Check the answerback adjustment function.
Check the answerback functions. (Refer to Keyless Entry System - On-vehicle Service - Enabling/disabling the Answerback Function).
Q: Does the answerback function work normally?
YES: No action to be taken.
NO: Go to Step 3.
STEP 3. Check trouble symptom.
Q: Which answerback function is defective?
Only the dome light: Go to Step 4.
Only the turn-signal lights: Go to Step 5.
Only the horns: Go to Step 6.
None of the dome light, the turn-signal lights, and the horn: Replace the ETACS-ECU. Check that the answerback functions work normally.
STEP 4. Check the dome light.
Q: Does the dome light illuminate normally?
YES: Replace the ETACS-ECU. Check that the answerback functions work normally.
NO: Refer to Inspection Procedure M-1 "Dome light, luggage compartment light
STEP 5. Check the hazard warning light.
Q: Do the hazard warning lights work normally?
YES: Replace the ETACS-ECU. Check that the answerback functions work normally.
NO: Refer to Inspection Procedure K-2 "Hazard warning lights do not flash when the hazard warning light switch is turned on."
STEP 6. Check the theft-alarm system (horn).
Q: Does the theft-alarm system work normally?
YES: Replace the ETACS-ECU. Check that the answerback functions work normally.
NO: Refer to Inspection Procedure N-2 "Horn does not sound when the theft-alarm is triggered."