Inspection Procedure C-5

INSPECTION PROCEDURE C-5: Central Door Locking System: Forgotten key prevention function does not work normally.

NOTE:
This troubleshooting procedure requires 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 forgotten key prevention function under the following conditions:

- Ignition key: inserted into the ignition key cylinder
- Door: open
- Door lock: being locked

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 ETACS-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" menu for the "ETACS ECU" menu.

Q. Is "OK" displayed for the "ETACS ECU" menu?

YES Go to Step 2.

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

STEP 2. Check the input signal by using "DATA LIST" menu of the SWS monitor.









Turn the ignition switch to the "ON" position before checking input signals from the ignition switch (IG1).
(1)Operate the scan tool MB991958 according to the procedure below to display "ETACS ECU."

.....Select "Interactive Diagnosis."

.....Select "System Select."

.....Select "SWS."

.....Select "SWS MONITOR."

.....Select "Data List."

.....Select "ETACS ECU."
(2)Check that normal conditions are displayed for the items described in the table below.





Q. Does scan tool MB991958 display "FRONT DOOR SW" as normal condition?

YES Go to Step 3.

NO Refer to Inspection Procedure M-5 "ETACS-ECU does not receive any signal from the door switches Inspection Procedure M-5."

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





Check the following switches and input signals:

- Key reminder switch
(1)Operate scan tool MB991958 according to the procedure below to display "Pulse check."

.....Select "Interactive Diagnosis."

.....Select "System Select."

.....Select "SWS."

.....Select "Pulse Checking."
(2)Check if scan tool MB991958 sounds or not.





Q. When the key reminder switch is operated, does scan tool MB991958 sound?

YES Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Immobilizer System. The forgotten key prevention function should work normally.

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