Inspection Procedure B-2
Tone Alarm: Light reminder tone alarm function does not work normally.Light 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."
CIRCUIT OPERATION
The ETACS-ECU operates the light reminder tone alarm function intermittently according to the following signals:
- Ignition switch (IG1): OFF
- Front door switch (LH): ON
- Taillight switch: ON
- Headlight switch: ON
The ETACS-ECU operates the light reminder tone alarm function intermittently under the following conditions.
- Ignition switch: LOCK position (key removed)
- Driver's door: OPEN
- Lighting Switch: Tail or Head position
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
- Trouble in input signal system
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- The ETACS-ECU may be defective
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991911: M.U.T.-III Main Harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness
STEP 1. Use scan tool MB991958 to select "ECU COMM Check" on the SWS monitor display.
Check the following ECUs:
- ETACS-ECU
- Column-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 MB991502 or MB991958. Connect special tool MB991911 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.
1. Connect the special tool. Refer to "How to connect SWS monitor."
2. Turn the ignition switch to the "LOCK" (OFF) position.
3. Operate scan tool MB991958 according to the procedure below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."
4. Scan tool MB991958 should show "OK" on the "ECU COMM Check" menu for the "ETACS ECU" menu.
Q: Is "OK" displayed on both the "ETACS ECU" and "COLUMN ECU" menus?
YES <"OK" is displayed for all the items> : Go to Step 2.
NO <"NG" is displayed on the "ETACS ECU" menu> : Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible."
NO <"NG" is displayed on the "COLUMN ECU" menu> : Refer to Inspection Procedure A-2 "Communication with the column switch (column-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 following switches:
- Ignition switch: OFF (key removed)
- Lighting switch: TAIL or HEAD
- Driver's door: open
- Front passenger's door: closed
1. Operate scan tool MB991958 according to the procedure below to display "LGT MONI. ALRM."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "BUZZER."
g. Select "LGT MONI. ALRM."
2. Check that normal conditions are displayed for 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 cannot be checked correctly.
Q: Does the scan tool MB991958 display the items "HEADLIGHT SW", "TAILLIGHT SW", "IG SW (IG1)", "FRONT DOOR SW", "H/L AUTO-CUT" and "BUZZER" as normal condition?
YES
NO
NO
NO
NO
NO
NO