Inspection Procedure N-7

INSPECTION PROCEDURE N-7: Transmitter: ETACS-ECU does not receive any signal from the lock, unlock, trunk or panic switch.

Receiver And Transmitter Communication Circuit:

CIRCUIT OPERATION
The ETACS-ECU receives signal through its receiver from the transmitter, and operates the keyless entry system according to the signal.

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the keyless entry transmitter does not work normally.

TROUBLESHOOTING HINTS
- The transmitter may be defective
- The ETACS-ECU may be defective

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Register the transmitter.

Register the transmitter. Refer to On-vehicle Service, How to register secret code. Programming and Relearning

Q: Can the transmitter be registered correctly?

YES : If the transmitter works normally, the input signal from the transmitter should be normal.

NO : Go to Step 2.

STEP 2. Check the transmitter battery.







Measure the voltage of the transmitter battery.
- The value should be approximately 2.5 - 3.2 volts.

Q: Is the measured voltage approximately 2.5 - 3.2 volts (battery positive voltage)?

YES : Go to Step 3.

NO : Replace the battery. If the transmitter can be registered normally, and operates normally, it indicates that the transmitter is sending normal signal to the ECU.

STEP 3. Check the transmitter.

Replace the transmitter and register the code. Refer to On-vehicle Service, How to register secret code.


Q: Can the transmitter be registered correctly?

YES : If the transmitter works normally, the input signal from the transmitter should be normal.

NO : Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. If the transmitter works normally, the input signal from the transmitter should be normal.