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
- Turn-signal light answerback function
- Horn answerback function

TECHNICAL DESCRIPTION (COMMENT)
The turn-signal lights and horn answerback functions can be disabled or enabled. However, the dome light answerback function can not be disabled.

TROUBLESHOOTING HINTS
- Malfunction of the turn-signal light
- 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
- MB991502: Scan Tool (MUT-II)

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 normally."

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 L-1 "Dome light does not illuminate."

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 J-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 M-2 "Tone alarm does not sound when the theft-alarm system is triggered."