Inspection Procedure 4
The Ignition Key Reminder Tone Alarm does not Stop Sounding by Removing the ignition Key. 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.
TECHNICAL DESCRIPTION (COMMENT)
It is possible that there is a malfunction of the input signal from the key reminder switch or the ETACS-ECU.
TROUBLESHOOTING HINTS
- Damaged harness wire or connector
- Malfunction of the ETACS-ECU
- Malfunction of the key reminder switch.
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 continuity of the key reminder switch.
1. Remove the driver's side under cover.
2. Remove the column covers, lower and upper.
3. Disconnect wiring connector D-16 from the key reminder switch and measure at the key reminder switch side.
4. Measure the resistance between terminal numbers 4 and 6.
Q: Is the resistance value less than two Ohms?
YES: Go to Step 4.
NO: Replace the key reminder switch. Then check that the malfunction is eliminated.
STEP 4. Check the input signal from the key reminder switch.
Check that the tone alarm stops sounding when terminal number 6 is grounded.
Q: Is the tone alarm stops sounding?
YES: Go to Step 5.
NO: Go to Step 6.
STEP 5. Check the key reminder switch connector D-16 for damage.
Q: Is the key reminder switch connector D-16 in good condition?
YES: Go to step 6.
NO: Repair or replace it. Refer to Harness Connector Inspection.
STEP 6. Check the harness wire between key reminder switch connector D-16 and body ground.
Q: Is the resistance wore between key reminder switch D-16 and body ground
YES: Replace the ETACS-ECU. Then Go to Step 7.
NO: Repair or replace it. Refer to Harness Connector Inspection.
STEP 7. Check the harness wire between key reminder switch connector D-1 6 and ETACS-ECU connector D-11.
NOTE: After checking intermediate connector C-72 and D-13, check the wires. If intermediate connector C-72 and D-13 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Is the harness wire between key reminder switch D-16 and ETACS-ECU connector D-11 in good condition?
YES: Go to Step 8.
NO: Repair or replace it. Refer to Harness Connector Inspection.
STEP 8. 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.