Inspection Procedure E-3

Keyless Entry System: Encrypted code cannot be registered

Encrypted Transmitter Code Circuit:

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 key reminder switch, hazard warning light switch 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
- The key reminder switch may be defective.
- The hazard warning light switch may be defective.
- The transmitter may be defective.
- The ETACS-ECU may be defective.
- The wiring harness may be damaged or the connectors) may have loose, corroded or damaged terminals, or terminals pushed back in the connector

Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)

STEP 1. Verify the trouble symptom.

Q: Can the encrypted code register mode be set?

YES: Refer to Inspection Procedure O-9 "ETACS-ECU dose not receive a signal from the lock or unlock switch."

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 MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.




1. Connect scan tool MB991502 to the data link connector.
2. Operate the scan tool MB991502 as follows:
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "PULSE CHECK."
3. Verify the scan tool MB991502 sounds or not.




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

Q: When the key reminder switch and the hazard warning light switch are operated, does scan tool MB991502 sound?

YES: Replace the ETACS-ECU. Verify that the encrypted code can be registered in the transmitter.

NO:
- Scan tool MB991502 does not sound when the ignition key is removed and reinserted: Refer to Inspection Procedure O-1 "ETACS-ECU does not receive a signal from the key reminder switch."
- Scan tool MB991502 does not sound when the hazard warning light switch is turned from "OFF" to "ON": Refer to Inspection Procedure O-2 "ETACS-ECU does not receive a signal from the hazard warning light switch."