Inspection Procedure E-2
E-2: Keyless Entry System: the Dome Light, the Hazard Warning Lights and the Horn Do Not Operate Through the Answerback FunctionHorn Circuit <2000 Models Without Theft-Alarm System>:
Connectors:
CIRCUIT OPERATION.
The turn-signal light and the horn answerback functions can be selected by the driver's desire (can be deactivated). However, the interior lights answerback function can not be deactivated. If all of these devices do not operate through the answerback function, the ETACS-ECU may be defective.
TROUBLESHOOTING HINTS
- Malfunction of the turn-signal light
- Malfunction of the horn
- Malfunction of the horn relay
- 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)
- MB991529: Diagnostic Trouble Code Check Harness
STEP 1. Check the answerback set condition.
Activate the answerback functions. (Refer to Keyless Entry System - Enabling/disabling the Answerback Function.)
Q: Does the answerback function work normally?
YES: There is no action to be taken.
NO: Go to Step 2.
STEP 2. Check trouble symptom.
Q: Which component(s) does not operate through the answerback?
Only the dome light: Go to Step 3.
Only the hazard warning lights: Go to Step 4.
Only the horn
Only the horn
None of the dome light, the turn-signal lights, and the horn: Replace the ETACS-ECU. The answerback function should work normally.
STEP 3. Check the dome light dimming function.
Q: Does the dome light dimming function work normally?
YES: Replace the ETACS-ECU. The answerback function should work normally.
NO: Solve the problem first. Refer to inspection Procedure L-1.
STEP 4. Check the hazard warning light operation.
Q: Do the hazard warning lights operate normally?
YES: Replace the ETACS-ECU. The answerback function should work normally.
NO: Solve the problem first. Refer to inspection Procedure J-2.
STEP 5. Check the theft-alarm horn operation.
Q: Does the horn work normally by the theft-alarm system?
YES: Replace the ETACS-ECU. The answerback function should work normally.
NO: Solve the problem first. Refer to inspection Procedure M-2.
STEP 6. Check the horn.
The horn should sound when the battery is connected as shown in the illustration.
Q: Does the horn sound?
YES: Go to Step 7.
NO: Replace the horn. The answerback function should work normally.
STEP 7. Check the horn relay.
Q: Is the theft-alarm horn relay in good condition?
YES: Go to Step 8.
NO: Replace it. The answerback function should work normally.
STEP 8. Check the horn relay power supply circuit at the theft-alarm horn relay connector A-15X.
1. Disconnect the horn relay connector A-15X and measure at the relay box side.
2. Measure the voltages between terminals 3, 4 and ground.
Q: Are the voltages approximately 12 volts (battery positive voltage)?
YES: Go to Step 11.
NO: Go to Step 9.
STEP 9. Check the horn relay connector A-15X for damage.
Q: Is horn relay connector A-15X in good condition?
YES: Go to Step 10.
NO: Repair or replace it. Refer to Harness Connector Inspection. The answerback function should work normally.
STEP 10. Check the harness wires between horn relay connector A-15X and fusible link (1).
NOTE: After checking intermediate connector C-66 and junction block connector C-77 and C-85, check the wires. If intermediate connector C-66 and junction block connector C-77 and C-85 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Are the harness wire between horn relay connector A-15X and fusible link (1) in good condition?
YES: There is no action to be taken.
NO: Repair them. The answerback function should work normally.
STEP 11. Check the horn relay connector A-15X and ETACS-ECU connector C-81 for damage.
Q: Are horn relay connector A-15X and ETACS-ECU connector C-81 in good condition?
YES: Go to Step 12.
NO: Repair or replace them. Refer to Harness Connector Inspection. The answerback function should work normally.
STEP 12. Check the harness wires between horn relay connector A-15X and ETACS-ECU connector C-81.
NOTE: After checking intermediate connector C-66, check the wires. If intermediate connector C-66 is damaged, repair or replace it. Refer to Harness Connector Inspection.
Q: Are the harness wires between horn relay connector A-15X and ETACS-ECU connector C-81 in good condition?
YES: Go to Step 13.
NO: Repair them. The answerback function should work normally.
STEP 13. Check the horn relay connector A-15X and horn connector A-29 for damage.
Q: Are horn relay connector A-15X and horn connector A-29 in good condition?
YES: Go to Step 14.
NO: Repair or replace them. Refer to Harness Connector Inspection. The answerback function should work normally.
STEP 14. Check the harness wire between horn relay connector A-15X and horn connector A-29.
Q: Is the harness wire between horn relay connector A-15X and horn connector A-29 in good condition?
YES: Go to Step 15.
NO: Repair it. The answerback function should work normally.
STEP 15. Check that the horn is installed properly.
NOTE: The horn is grounded to the body through the installation bolts.
Q: Is the horn installation in good condition?
YES: Replace the ETACS-ECU. The answerback function should work normally.
NO: Repair it. The answerback function should work normally.