Inspection Procedure E-3
TECHNICAL DESCRIPTION (COMMENT)The ETACS-ECU activates the encrypted code register mode according to the following switch signals.
- Key reminder switch
- Hazard warning light switch
If the encrypted code register mode is not set, the relevant input signal circuit or the ETACS-ECU may be defective.
If a transmitter can not be registered although the encrypted code register mode is set, 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)
MB991529: Diagnostic Trouble Code Check Harness
STEP 1. Check the trouble symptom.
If the encrypted code register mode is not set, go to Step 2.
If a transmitter can not be registered although the encrypted code register mode is set, go to Step 3.
STEP 2. Check the input signal.
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 "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.
1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the input signal enters.
If one of the input signal checks shows a defect, check the relevant input circuit.
If none of the input signal checks shows a defect, replace the ETACS-ECU.
Check that the transmitter can be registered.
STEP 3. Check the transmitter.
If the transmitter battery has been changed but the encrypted code cannot be registered, replace the transmitter. Check that the transmitter can be registered.
If the transmitter can not be registered, replace the ETACS-ECU. Check that the transmitter can be registered.