Inspection Procedure E-2

Keyless Entry System: The dome light, hazard warning lights (turn-signal lights) and horn do not operate through the answerback function.

CIRCUIT OPERATION
The ETACS-ECU operates the following functions when it receives a 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 or horn answerback functions can be disabled. However, the dome light answerback function can be disabled.

TROUBLESHOOTING HINTS
- The hazard warning lights (turn-signal lights) may be defective.
- The horn may be defective.
- The dome light may be defective.
- The ETACS-ECU may be defective.
- The wiring harness may be damaged or the connectors) may have loose, corroded or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A

STEP 1. Verify 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 network normally."

STEP 2. Verify the answerback adjustment function.

Check the answerback functions. (Refer to Keyless Entry System - On-vehicle Service - Enabling/disabling the Answer back Function).

Q: Does the answerback function work normally?

YES: No action is necessary and testing is complete.

NO: Go to Step 3.

STEP 3. Verify the trouble symptom.

Q: Which answerback function is defective?

Only the dome light : Go to Step 4.
Only the hazard warning lights (turn-signal lights) : Go to Step 5.
All functions do not work [dome light, hazard warning lights (turn-signal lights) and horn]. : Replace the ETACS-ECU. Verify that the answerback functions work normally.

STEP 4. Verify the dome light.

Q: Does the dome light illuminate normally?

YES: Replace the ETACS-ECU. Verify that the answerback functions work normally.

NO: Refer to Inspection Procedure M-1 "The front dome light and rear dome light do not illuminate or go out normally.

STEP 5. Verify the hazard warning light.

Q: Do the hazard warning lights work normally?

YES: Replace the ETACS-ECU. Verify 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."