Inspection Procedure E-3

Keyless Entry System: Encrypted code cannot be registered.

Encrypted Transmitter Code Register Mode:

CIRCUIT OPERATION
The ETACS-ECU operates the encrypted code register mode according to the following signals:
- Key reminder switch
- Hazard warning light switch

TECHNICAL DESCRIPTION (COMMENT)
If the encrypted code register mode can not be set, the input circuits from the switches described in "CIRCUIT OPERATION" or the ETACS-ECU may be defective.

If the encrypted code register mode can be set but the transmitter can not be registered, the transmitter or the ETACS-ECU may be defective.

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
- 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

STEP 1. Verify trouble symptom.

Q: Can the encrypted code register mode be set?

YES: Go to Step 3.

NO: Go to Step 2.

STEP 2. Check the input signal (by using the Pulse check mode of the monitor).
Check the input signals from the following switches:
- Key reminder switch
- Hazard warning light switch

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 to the data link connector. Refer to "How to connect SWS monitor."
2. Operate scan tool MB991958 according to the procedure below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."

3. If the switches (see table), which are applicable for the input signal check, are operated.




4. Check scan tool MB991958 sounds or not.

Q: When the key reminder switch and the hazard warning light switch are operated, does scan tool MB991958 sound in each case?

Buzzer of scan tool MB991958 sounds normally. : Replace the ETACS-ECU. Verify that the encrypted code can be registered in the transmitter.

scan tool MB991958 does not sound when the ignition key is removed and reinserted : Refer to Inspection Procedure O-1 "The ETACS-ECU does not receive any signal from the key reminder switch."

scan tool MB991958 does not sound when the hazard warning light switch is turned from "OFF" to "ON" : Refer to Inspection Procedure O-2 "The ETACS-ECU does not receive any signal from the hazard warning light switch."

STEP 3. Check the transmitter.

Q: When the transmitter's battery is replaced, can the encrypted code be registered?

YES: No action is necessary and testing is complete.

NO: Replace the transmitter. If the encrypted code can not be registered by means of the new transmitter, replace the ETACS-ECU. Verify that the encrypted code can be registered in the transmitter.