Inspection Procedure E-3

INSPECTION PROCEDURE E-3: Keyless Entry System: Encrypted code cannot be registered.





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 cannot 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 cannot 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 or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

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





(1)
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.

Connect scan tool MB991958.Refer to "How to connect SWS monitor How to Connect SWS Monitor."
(2)Operate scan tool MB991958 according to the procedure below to display "Pulse check."

.....Select "Interactive Diagnosis."

.....Select "System select."

.....Select "SWS."

.....Select "Pulse Checking."
(3)Check the switches (see table below) 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. When the ETACS-ECU is replaced, register the encrypted code. Encrypted Code Registration Criteria Table. 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 N-1 "ETACS-ECU does not receive any signal from the key reminder switch Inspection Procedure N-1."

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

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 cannot be registered using the new transmitter, replace the ETACS-ECU. Verify that the encrypted code can be registered in the transmitter.