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 Buzzer 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 (Refer to 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. (Refer to Diagnostic Trouble Code Chart). 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 ( Refer to Actuator Test Table). 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). Refer to general (Electrical), Harness Connector Inspection. Check that the outer tone alarm works normally.

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

1. Disconnect KOS-ECU connector C-05 and outer tone alarm connector F-21, and check the wiring harness.




2. Check the wiring harness between KOS-ECU connector C-05 (terminal No.35) and outer tone alarm connector F-21(terminal No.1).

OK: Continuity exists (2 Ohms or less)






3. Check the wiring harness between KOS-ECU connector C-05 (terminal No.37) and outer tone alarm connector F-21(terminal No.2).

OK: Continuity exists (2 Ohms or less)

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

YES: Go to Step 6.

NO (KOS-ECU connector C-05 terminal No.35 - outer tone alarm connector F-21 terminal No.1.) : Repair the wiring harness between KOS-ECU connector C-05 (terminal No.35) and outer tone alarm connector F-21(terminal No.1).

NO (KOS-ECU connector C-05 terminal No.37 - outer tone alarm connector F-21 terminal No.2.) : Repair the wiring harness between KOS-ECU connector C-05 (terminal No.37) and outer tone alarm connector F-21(terminal No.2).

STEP 6. Check the wiring harness between the outer tone alarm connector F-21 (terminal Nos. 1, 2) and the ground for short circuit.

1. Disconnect outer tone alarm connector F-21, and check the wiring harness.




2. Check the wiring harness between outer tone alarm connector F-21 (terminal No. 1) and ground

OK: No continuity




3. Check the wiring harness between outer tone alarm connector F-21 (terminal No. 2) and ground

OK: No continuity

Q: Is the wiring harness between outer tone alarm connector F-21 (terminal Nos. 1, 2) and the ground in good condition?

YES: Go to Step 7.

NO [outer tone alarm connector F-21 terminal No.1 - ground.] : Repair the wiring harness between outer tone alarm connector F-21 (terminal No.1) and ground.

NO [outer tone alarm connector F-21 terminal No.2 - ground.] : Repair the wiring harness between outer tone alarm connector F-21 (terminal No.2) and the ground.

STEP 7. 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 (Refer to ID Code Registration Necessity Judgment Table).