Inspection Procedure 6

INSPECTION PROCEDURE 6: Ignition "LOCK (OFF)" position-linked door unlock function does not operate [M/T, CVT, TC-SST].

CAUTION: Before replacing the ECU, ensure that the input and output signal circuits are normal.

COMMENTS ON TROUBLE SYMPTOM
If a door is not unlocked when the ignition switch is turned to the LOCK position, a malfunction of the CAN bus line, ignition switch or ETACS-ECU is suspected. Also, the ignition "LOCK" position-linked door unlock function may have been "Disabled" with the customise function.

PROBABLE CAUSES
- Malfunction of CAN bus line
- Malfunction of ETACS-ECU
- Malfunction of ignition switch
- Damaged wiring harness and connectors

DIAGNOSIS PROCEDURE

STEP 1. Checking central door unlocking operation
Check that the central door locking system works normally.


Q: Is the check result normal?

YES : Go to Step 2.

NO : Refer to trouble symptom chart. Symptom Chart

STEP 2. Check the customize function.
Check that the following other than "Disabled" is set for "Auto door unlock by ignition LOCK position" with the customize function.
- Always (LOCK pos)


Q: Is the check result normal?

YES : Go to Step 3.

NO : Set the function as mentioned above other than "Disabled" for "Auto door unlock by ignition LOCK position" with the customize function.

STEP 3. Using scan tool MB991958, read CAN bus 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)".
2. Turn the ignition switch to the "ON" position.
3. Check whether the CAN bus lines related DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.


Q: Is the DTC set?

YES : Repair the CAN bus line (Refer to Controller Area Network, CAN bus diagnostics table).

NO : Go to Step 4.

STEP 4. Check the ignition switch.
Check that the ignition switch works normally.


Q: Is the check result normal?

YES : Go to Step 5.

NO : Repair the ignition switch (Refer to Chassis Electrical - Ignition Switch Troubleshooting/Inspection Procedure 2 - Malfunction of the Ignition Switch Power Supply System.

STEP 5. Retest the system.
Check that turning the ignition switch to the LOCK position unlocks the all doors.


Q: Is the check result normal?

YES : Intermittent malfunction (Refer to General (Body and Chassis) - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.

NO : Replace the ETACS-ECU.