Inspection Procedure B-1

Tone Alarm: Ignition key reminder tone alarm function does not work normally.

Ignition Key Reminder Tone Alarm Function:

NOTE: This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor." How To Use SWS Monitor

CIRCUIT OPERATION
The ETACS-ECU operates this function in accordance with the input signals below.
- Ignition switch (IG1)
- Key reminder switch
- Driver's door switch

If this function does not work normally, these input signal circuit(s) or the ETACS-ECU may be defective.

TECHNICAL DESCRIPTION (COMMENT)
If the function does network normally, the input circuit system from the switches or the ETACS-ECU may be defective (refer to "CIRCUIT OPERATION").

TROUBLESHOOTING HINTS
- The key reminder switch may be defective
- The front door switches may be defective
- The ETACS-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
- MB991813: SWS monitor kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: Probe Harness
- MB991854: SWS Monitor Harness (For 13-pin)

STEP 1. Use scan tool MB991958 to select "ECU COMM CHK" on the SWS monitor display.

Check the ETACS-ECU.

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 to the data link connector (16-pin).
2. Connect SWS monitor harness MB991854 to the data link connector (13-pin).
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Operate the scan tool MB991958 according to the procedure below to display "ECU COMM CHECK."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "ECU COMM CHK".

5. Scan tool MB991958 should show "OK" on the "ECU COMM CHK" menu for the "ETACS ECU" menu.

Q: Is "OK" displayed on the "ETACS ECU" menu?

YES: Go to Step 2.

NO: Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible."

STEP 2. Check the input signal by using "FUNCTION DIAG." menu of the SWS monitor.

Check the input signals from the switches in the following conditions:
- Turn the ignition switch to the OFF position, (key inserted)
- Open the driver's door. (The front door switch (LH) is turned to the ON position.)
- Close the front passenger's door. (The front door switch (RH) is turned to the OFF position.)




1. Operate the scan tool MB991958 according to the procedure below to display "KEY RMND. ALM."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "FUNCTION DIAG."
e. Select "BUZZER."
f. Select "KEY RMND. ALM."




2. Check that normal conditions are displayed on the items described in the table.

NOTE: The scan tool display changes when the driver's or the front passenger's door is opened. If any of the doors is open, the system can not be checked correctly.

Q: Are normal conditions displayed on the "IG SW (IG1)", "FRONT DOOR SW" and "BUZZER"?

YES : Replace the ETACS-ECU. Verify that the ignition key reminder tone alarm function should now work normally.

NO : Refer to Inspection Procedure N-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."

NO : Refer to Inspection Procedure N-5 "ETACS-ECU does not receive a signal from the front door switches."

NO : Normal condition is not displayed on the "BUZZER": Go to Step 3.

STEP 3. Check the input signal (by using the pulse check mode of the monitor).

Check the input signals from the key reminder switch.




1. Operate the scan tool MB991958 according to the procedure below to display "PULSE CHECK."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "PULSE CHECK."

2. Check whether scan tool MB991958 sounds or not when the ignition key is removed and reinserted.

Q: Does scan tool MB991958 sound when the ignition key is removed and reinserted?

YES: Replace the ETACS-ECU. Verify that the ignition key reminder tone alarm function should now work normally.

NO: Refer to Inspection Procedure 0-1 "ETACS-ECU does not receive a signal from the key reminder switch."