Inspection Procedure B-2
INSPECTION PROCEDURE B-2: Tone Alarm: Light reminder tone alarm function does not work normally.
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 the light reminder tone alarm function under the following conditions:
- Ignition switch: "LOCK" (OFF) position
- Ignition key: Removed from the ignition key cylinder
- Driver's door: open
- Taillights or headlights: ON
TECHNICAL DESCRIPTION (COMMENT)
If the function does not work 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
- MB991910: M.U.T.-III Main Harness A
- MB991813: SWS Monitor Kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: 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 switch (column-ECU)
(1)
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. Connect special tool MB991910 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.
Connect the special tool. Refer to "How to connect SWS monitor 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."
.....Select "Interactive Diagnosis."
.....Select "System Select."
.....Select "SWS."
.....Select "SWS MONITOR."
.....Select "ECU COMM Check."
(4)Scan tool MB991958 should show "OK" on the "ECU COMM Check" menus for both the "ETACS ECU" and the "COLUMN ECU" menus.
Q. Are "OK" displayed for both the "ETACS ECU" and "COLUMN ECU" menus?
"OK" are displayed for all the items : Go to Step 2.
"NG" is displayed for the "ETACS ECU" menu : Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible Inspection Procedure A-3."
"NG" is displayed for the "COLUMN ECU" menu : Refer to Inspection Procedure A-2 "Communication with the column switch (column-ECU) is not possible Inspection Procedure A-2."
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
- Passenger's door: closed
(1)Operate scan tool MB991958 according to the procedure below to display "LGT MONI. ALRM."
.....Select "Interactive Diagnosis."
.....Select "System Select."
.....Select "SWS."
.....Select "SWS MONITOR."
.....Select "Function Diag."
.....Select "BUZZER."
.....Select "LGT MONI. ALRM."
(2)Check that normal conditions are displayed for the items described in the table below.
NOTE:
Scan tool MB991958 display changes when the driver's or the passenger's door is opened. If any of the doors is open, the system cannot be checked correctly.
Q. Does scan tool MB991958 display "HEADLIGHT SW", "TAILLIGHT SW", "IG SW (IG1)", "FRONT DOOR SW", "H/L AUTO-CUT" and "BUZZER" as normal condition?
Normal conditions are displayed for all the items : Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Immobilizer System. The light reminder tone alarm function should now work normally.
Normal condition is not displayed for "HEADLIGHT SW" : Refer to Inspection Procedure M-6 "ETACS-ECU does not receive any signal from the headlight switch Inspection Procedure M-6."
Normal condition is not displayed for "TAILLIGHT SW" : Refer to Inspection Procedure M-6 "ETACS-ECU does not receive any signal from the taillight switch Inspection Procedure M-6."
Normal condition is not displayed for "IG SW (IG1)" : Refer to Inspection Procedure M-2 "ETACS-ECU does not receive any signal from the ignition switch (IG1) Inspection Procedure M-2."
Normal condition is not displayed for "FRONT DOOR SW" : Refer to Inspection Procedure M-5 "ETACS-ECU does not receive any signal from the door switches Inspection Procedure M-5."
Normal condition is not displayed for "H/L AUTO-CUT" : Refer to Inspection Procedure I-9 "Headlight automatic shutoff function does not work normally Inspection Procedure I-9."
Normal condition is not displayed for "BUZZER" : Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Immobilizer System. The light reminder tone alarm function should now work normally.