Inspection Procedure E-3: Keyless Entry Encrypted Code Cannot Be Registered

NOTE: To perform this test, MUT-II Scan Tool (MB991502) and Test Harness Set (MB991223) must be used.

CAUTION: To prevent damage to Scan Tool (MB991502), always turn the ignition switch to the LOCK (OFF) position before connecting or disconnecting scan tool.

If encrypted code register mode is not set, go to next step. If encrypted code mode is set and transmitter cannot be registered, go to step 3.

Connect scan tool to the Data Link Connector (DLC). Check input signals for:

Key reminder switch.
Hazard warning light switch.

If the switches which are applicable for the input signal check are operated, check if scan tool sounds or not. See DOOR LOCK INPUT SIGNAL TEST table. When the key reminder switch and the hazard warning light switch are operated, does scan tool sound in each case?

If YES, replace the ETACS-ECU.
If NO, and scan tool does not sound when the ignition key is removed and reinserted, refer to INSPECTION PROCEDURE N-1: ETACS-ECU DOES NOT RECEIVE A SIGNAL FROM THE KEY REMINDER SWITCH .
If NO, and scan tool does not sound when the hazard warning light switch is turned from OFF to ON, refer to INSPECTION PROCEDURE N-2: THE ETACS-ECU DOES NOT RECEIVE ANY SIGNAL FROM THE HAZARD WARNING LIGHT SWITCH .

After repair, check that the encrypted code can be registered in the transmitter.

DOOR LOCK INPUT SIGNAL TEST

Item Name	Check Conditions
Key Reminder Switch	Remove Then Reinstall Ignition Key
Hazard Warning Light Switch	Turn Hazard Warning Light Switch From OFF To ON Position.

Replace transmitter battery. When the transmitter's battery is replaced, can the encrypted code be registered?
- If YES, no action to be taken.
- If NO, replace the transmitter. See REMOTE KEYLESS ENTRY SYSTEMS article. If the encrypted code can not be registered by means of the new transmitter, replace the ETACS-ECU. Check that the encrypted code can be registered in the transmitter.