Inspection Procedure 18

Inspection Procedure 18: Outer Tone Alarm Does Not Sound.

CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

Outer Tone Alarm Circuit:

TECHNICAL DESCRIPTION (COMMENT)
The outer tone alarm sounds under the following conditions.
- When the door is locked or unlocked with the keyless or keyless operation function
- Door lock does not operate.
- The keyless operation key is brought out of the vehicle.

TROUBLESHOOTING HINTS
- Malfunction of the antenna and outer tone alarm assembly
- Malfunction of the KOS-ECU
- Damaged wiring harness and connectors

DIAGNOSIS

STEP 1. Check the customize function.

Check that either of the followings other than "Not sound tone alarm" is set for "Tone alarm answer back" with the customization function.
- At keyless
- At F.A.S.T.
- At Both

Q: Is the check result normal?

YES : Go to Step 2.

NO : Set either of the followings other than "Tone alarm answer back" with the customization function. Programming and Relearning

STEP 2. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.







1. Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III)." How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check whether the KOS-ECU related DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Diagnose the KOS-ECU. Diagnostic Trouble Code Descriptions

NO : Go to Step 3.

STEP 3. Using scan tool MB991958, read the actuator test.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.







1. Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III)." How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check that the outer tone alarm sounds. Keyless Operation System (KOS)
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 6.

NO : Go to Step 4.

STEP 4. Check KOS-ECU connector C-05 and outer tone alarm connector F-21 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are KOS-ECU connector C-05 and outer tone alarm connector F-21 in good condition?

YES : Go to Step 5.

NO : Repair or replace the damaged component(s). Check that the outer tone alarm works normally.

STEP 5. Check the wiring harness between KOS-ECU connector C-05 (terminal Nos. 35 and 37) and outer tone alarm connector F-21 (terminal Nos. 1 and 2).

- Check the power supply and ground lines for open circuit.

NOTE: Also check intermediate connectors C-42, D-17 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connectors C-42, D-17 is damaged, repair or replace the damaged component(s).

Q: Are the wiring harness between KOS-ECU connector C-05 (terminal Nos. 35 and 37) and outer tone alarm connector F-21 (terminal Nos. 1 and 2) in good condition?

YES : Go to Step 6.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Check that the outer tone alarm works normally.

STEP 6. Check of the troubles

Check that the outer tone alarm sounds when the outer tone alarm sounding conditions are met.

Q: Is the check result normal?

YES : The diagnosis is complete.

NO : Replace KOS-ECU and register the ID codes.