Inspection Procedure E-2
Keyless Entry System: The front dome Light, the Turn-signal Lights and the Horn do not Operate Through the Answerback FunctionConnectors:
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 dome light
- Malfunction of the horn
- 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 configuration function.
Q: Has the answerback function been enabled by means of the adjustment function?
YES: Go to Step 3.
NO: Enable the answerback function by means of the adjustment function. Check that the answerback functions work normally.
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 horn : Go to Step 6.
None of the dome light and 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 K-1 "Front dome light, rear dome light and luggage compartment light do not illuminate or go out normally."
STEP 5. Check the hazard warning light.
Q: Does the hazard warning light work normally?
YES: Replace the ETACS-ECU. Check that the answerback functions work normally.
NO: Refer to Inspection Procedure L-2 "Hazard warning lights do not flash when the hazard warning light switch is turned on."
STEP 6. Check the horn operation.
Q: Does the horn work normally?
YES: Go to Step 19.
NO: Go to Step 7.
STEP 7. Check which horn is defective.
Q: Which horn does not sound?
horn (HI): Go to Step 8.
horn(LO): Go to Step 11.
horn (HI or LO): Go to Step 15.
STEP 8. Check the horn.
Connect the battery as shown, and check that the horn sounds.
Q: Is the horn normal?
YES: Go to Step 9.
NO: Replace the horn. Check that the horn sounds normally.
STEP 9. Check horn relay connector A-05X and horn (HI) connector A-18 for damage.
Q: Are horn relay connector A-05X and horn (HI) connector A-18 in good condition?
YES: Go to Step 10.
NO: Repair or replace the connector. Refer to Harness Connector Inspection-Check that the horn sounds normally.
STEP 10. Check the wiring harness between horn relay connector A-05X and horn (HI) connector A-18.
Q: Is the wiring harness between horn relay connector A-10X and horn (HI) connector A-18 in good condition?
YES: Go to Step 11.
NO: Repair the wiring harness. Check that the horn sounds normally.
STEP 11. Check the horn.
Connect the battery as shown, and check that the horn sounds.
Q: Is the horn normal?
YES: Go to Step 12.
NO: Replace the horn. Check that the horn sounds normally.
STEP 12. Check horn relay connector A-05X and horn (LO) connector A-19 for damage.
Q: Are horn relay connector A-05X and horn (LO) connector A-19 in good condition?
YES: Go to Step 13.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the horn sounds normally.
STEP 13. Check the wiring harness between horn relay connector A-05X and horn (LO) connector A-19.
Q: Is the wiring harness between horn relay connector A-05X and horn (LO) connector A-19 in good condition?
YES: Go to Step 14.
NO: Repair the wiring harness. Check that the horn sounds normally.
STEP 14. Check the fit of the horn.
When the theft-alarm system is triggered, check the fit of the horn (HI or LO) which does not sound.
NOTE: The horn is grounded to the vehicle body via its mounting bolt.
Q: Is the horn installed correctly.
YES: No action to be taken.
NO: Install the horn correctly. Check that the horn sounds normally.
STEP 15. Check the horn relay.
Q: Is the horn relay normal?
YES: Go to Step 16.
NO: Replace the horn relay. Check that the horn sounds normally.
STEP 16. Measure at horn relay connector A-05X in order to check the fusible link 2. line of power supply system to the horn relay.
1. Disconnect horn relay connector A-05X, and measure at the relay box side.
2. Measure the voltage between terminal numbers 2, 4 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).
Q: Does the measured voltage correspond with this range?
YES: No action to be taken.
NO: Go to Step 17.
STEP 17. Check horn relay connector A-05X for damage.
Q: Are horn relay connector A-05X in good condition?
YES: Go to Step 18.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the horn sounds normally.
STEP 18. Check the wiring harness between horn relay connector A-05X and the battery.
Q: Is the wiring harness between horn relay connector A-05X and the battery in good condition?
YES: No action to be taken.
NO: Repair the wiring harness. Check that the horn sounds normally.
STEP 19. Check rear horn relay connector A-05X and ETACS-ECU connector C-227 for damage.
Q: Are horn relay connector A-05X and ETACS-ECU connector C-227 in good condition?
YES: Go to Step 20.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the horn sounds normally.
STEP 20. Check the wiring harness between horn relay connector A-05X and ETACS-ECU connector C-227.
NOTE: Also check intermediate connector C-129 and joint connector C-101. If intermediate connector C-129 or joint connector C-101 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between horn relay connector A-05X and ETACS-ECU connector C-227 in good condition?
YES: Replace the ETACS-ECU. Check that the horn sounds normally.
NO: Repair the wiring harness. Check that the horn sounds normally.