Inspection Procedure 4: The theft-alarm horn does not sound while the theft-alarm Is triggered. < Vehicles without theft-alarm sensor >: Diagnosis

WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

STEP 1. Using scan tool (M.U.T.-III), read the diagnostic trouble code.
Check if DTC is stored in the ETACS-ECU.

CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
1. Connect scan tool (M.U.T.-III). Refer to "HOW TO CONNECT SCAN TOOL (M.U.T.-III) ."
2. Turn the ignition switch to the "ON" position.
3. Check whether the ETACS-ECU related DTC is stored.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC stored?
- YES: Diagnose the ETACS-ECU. Refer to DIAGNOSTIC TROUBLE CODE CHART .
- NO: Go to Step 2.
STEP 2. Check the theft-alarm horn relay.
Refer to HORN RELAY CHECK .

Q: Is the theft-alarm horn relay in good condition?
- YES: Go to Step 3.
- NO: Replace the theft-alarm horn relay.
STEP 3. Voltage measurement at the theft-alarm horn relay connector
1. Remove the relay, and measure at the relay box side.
2. Measure the voltage between the theft-alarm horn relay connector (power supply terminal) and ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the check result normal?
- YES: Go to Step 5
- NO: Go to Step 4
STEP 4. Check of open circuit in power supply line between the fusible link and theft-alarm horn relay connector.
Q: Is the check result normal?
- YES: The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
- NO: Repair the connector(s) or wiring harness.
STEP 5. Check the theft-alarm horn relay work normally.
Connect the battery as shown, and verify that the horn sounds.

Q: Does the theft-alarm horn relay work normally?
- YES: Go to Step 6.
- NO: Replace the theft-alarm horn, and go to Step 6.
  
  Fig 1: Checking Theft-Alarm Horn Relay Work Normally
STEP 6. Check of open circuit in power supply line between the theft-alarm horn relay connector and theft-alarm horn connector.
Q: Is the check result normal?
- YES: Go to Step 7.
- NO: Repair the connector(s) or wiring harness.
STEP 7. Check of open circuit in HORN line between the theft-alarm horn relay connector and ETACS-ECU connector.
Q: Is the check result normal?
- YES: Go to Step 8.
- NO: Repair the connector(s) or wiring harness.
STEP 8. Retest the theft-alarm system.
Check that the theft-alarm works normally.

Q: Does the theft-alarm system work normally?
- YES: he trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
- NO: Replace the ETACS-ECU.