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)
Is 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
- Malfunction of the key reminder switch
- Malfunction of the hazard warning light switch
- Malfunction of the transmitter
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

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

STEP 1. Check 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).

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

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

YES: Replace the ETACS-ECU. Check 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 M-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 M-2 "ETACS-ECU does not receive a 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 to be taken.

NO: Replace the transmitter. 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.