Inspection Procedure 3
The ignition Key Hole Illumination Light does not Go out when the Ignition Key is Turned to the "ON" Position. (However, it Goes out after 15 Seconds.) The ignition key Reminder Tone Alarm does not Stop Sounding When the Ignition Key is Turned to the "ON" Position (The Tone Alarm stops Sounding by Closing the Driver's Door.)CIRCUIT OPERATION
- The ETACS-ECU monitors the ignition switch by detecting voltage from the ignition switch.
- The ETACS-ECU judges that the driver's side door is opened or closed by detecting voltage from the front door switch (LH).
- When the driver's door is opened (door switch on), the ignition key hole illumination light will illuminate. When the driver's door is closed (door switch off), the ignition key hole illumination light will go out within 15 seconds.
- When the driver's door is opened without removing the ignition key, the tone alarm will sound intermittently to remind that the ignition key has not been removed.
TECHNICAL DESCRIPTION (COMMENT)
The input signal from the ignition switch may be defective, or the ETACS-ECU may be defective. If the multi-purpose fuse is blown, the harness may be short circuited.
TROUBLESHOOTING HINTS
- Damaged harness wire or connector
- Malfunction of the ETACS-ECU
DIAGNOSIS
Required Special Tools:
- MB991529: Diagnostic Trouble Code Check Harness
- MB991502: Scan Tool (MUT-II)
STEP 1. Check the input signal from the ignition switch (by using scan tool MB991502).
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. Check that the tone alarm of the scan tool MB991502 sounds when the ignition key is moved from the "LOCK" position to the "ON" position.
Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters?
YES: Replace the ETACS-ECU. Check that the malfunctions eliminated.
NO: Go to Step 3.
STEP 2. Check the input signal from the ignition switch (by using a voltmeter).
Check the input signals from the following switches:
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 ignition key is moved from the "LOCK" position to the "ON" position.
Q: Does the voltmeter indicator deflect?
YES: Replace the ETACS-ECU. Check that the malfunctions eliminated.
NO: Go to Step 3.
STEP 3. Check the input signal from the driver's side door switch.
1. Disconnect the ETACS-ECU connector D-11 and measure at the junction block side.
2. Turn the ignition switch "ON".
3. Measure the voltage between terminal number 3 and ground.
Q: Is the voltage approximately 12 volts (battery positive voltage)?
YES: Replace the ETACS-ECU. Check that the malfunction is eliminated.
NO: Go to Step 4.
STEP 4. Check the ETACS-ECU connector D-11 for damage.
Q: IS the ETACS-ECU connector D-11 in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection.
STEP 5. Check the harness wires between the ignition switch (IG1) and ETACS-ECU connector D-11.
NOTE: After inspecting junction block D-08, inspect the wire. If junction block D-08 is damaged, repair or replace it. Refer to Harness Connector Inspection.
Q: Are the harness wire between the ignition switch (IG1) and ETACS-ECU connector D-11 in good condition?
YES: Go to step 6.
NO: Repair or replace it. Refer to Harness Connector Inspection.
STEP 6. Recheck for malfunction.
Q: Is a malfunction eliminated?
YES: This diagnosis is complete. (If no malfunctions are not found in all steps, an intermittent malfunction is suspected. Refer to How to Use Troubleshooting/Inspection Service Point.)
NO: Go to step 1.