Inspection Procedure O-9

Transmitter: The ETACS-ECU does not receive any signal from the lock or unlock switch.

Transmitter Input 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 systems described in "CIRCUIT OPERATION" do network normally.

TROUBLESHOOTING HINTS
- The RKE 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.
Refer to Keyless Entry System, On-vehicle Service, How to register secret code.

Q: Can the transmitter be registered correctly?

YES: If the systems described in "CIRCUIT OPERATION" work 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 the systems described in "CIRCUIT OPERATION" operate normally, it indicates that the transmitter is sending normal signal to the ECU.

STEP 3. Check the transmitter.
Use another transmitter to register the encrypted code. Refer to Keyless Entry System, On-vehicle Service, How to register secret code.

Q: Can the transmitter be registered correctly?

YES: If the systems described in "CIRCUIT OPERATION" work normally, the input signal from the transmitter should be normal.

NO: Replace the ETACS-ECU. If the systems described in "CIRCUIT OPERATION" work normally, the input signal from the transmitter should be normal.