H - Charts
H-1: Ignition Key Hole Illumination Light: Ignition Key Hole Illumination Light Does Not Work Normally.Ignition Key Hole Illumination Light Circuit:
Connectors:
CIRCUIT OPERATION
The ETACS-ECU illuminates the ignition key hole illumination light when the ignition switch is turned to "LOCK" (OFF) or "ACC" position and the driver's door is opened. The ignition key hole illumination light goes off 30 seconds after closing the drive's door. Also, the ignition key hole illumination light illuminates for 30 seconds after removing the ignition key.
TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU illuminates the ignition key hole illumination light according to the input signals from the following switches:
Ignition switch (IG1)
- Key reminder switch
- Driver's door switch
If the ignition key hole illumination light does not illuminate, the relevant input signal circuit, the key reminder switch (Ignition key hole illumination light bulb) or the ETACS-ECU may be defective.
TROUBLESHOOTING HINTS
- Malfunction of the driver's door switch
- Malfunction of the key reminder switch (Key reminder switch or ignition key hole illumination light bulb)
- 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 method of the Input signal
Q: Which is to be used, the scan tool or the voltmeter to check the input signal?
Scan tool MB991502: Go to Step 2.
Voltmeter: Go to Step 3.
STEP 2. Check the input signal (by using scan tool MB991502).
Check the input signals from the following switches:
- Ignition switch (IG1)
- Key reminder switch
- Driver's side seat belt switch
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool M5991502.
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.
Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters?
YES: Go to Step 4.
NO: Check the relevant input signal circuit.
STEP 3. Check the Input signal (by using a voltmeter).
Check the input signals from the following switches:
- Ignition switch (IG1)
- Key reminder switch
- Driver's side seat belt switch
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.
Q: Does the voltmeter indicator deflect?
YES: Go to Step 4.
NO: Check the relevant input signal circuit.
STEP 4. Check the seat belt warning light circuit at the ETACS-ECU connector C-82.
Disconnect the ETACS-ECU connector C-82 and measure at the harness side.
1. Connect terminal 15 to the ground.
Q: Does the seat belt warning light illuminate?
YES: Replace the ETACS-ECU. The ignition hole illumination light should work normally.
NO: Go to Step 5..
STEP 5. Check the ignition hole illumination light bulb.
Q: Is the Ignition hole illumination light bulb in good condition?
YES: Go to Step 6.
NO: Replace it. The ignition hole illumination light should work normally.
STEP 6. Check the key reminder switch (ignition key hole illumination).
1. Disconnect the key reminder switch connector C-59.
2. Remove the ignition key hole illumination light bulb. Then measure the resistance between the bulb terminals.
3. Install the bulb to the key remainder switch, and then measure the resistance between connector C-59 terminal 1 and 2. The resistance reading at this time should be much the same as the resistance measured at Step (2).
Q: Are the two resistance values extremely different each other?
YES: Repair or replace the key reminder switch. The ignition key hole illumination light should work normally.
NO (much the same): Go to Step 7.
STEP 7. Check the key reminder switch (ignition key hole illumination light) power supply circuit at the key reminder switch connector C-59.
1. Disconnect the key reminder switch connector C-59 and measure at the harness side.
2. Measure the voltage between terminal 2 and ground.
Q: Is the voltage approximately 12 volts (battery positive voltage)?
YES: Go to Step 10.
NO: Go to Step 8.
STEP 8. Check the key reminder switch connector C-59 for damage.
Q: Is key reminder switch connector C-59 in good condition?
YES: Go to Step 9.
NO: Repair or replace it. Refer to Harness Connector Inspection. The ignition key hole illumination light should work normally.
STEP 9. Check the harness wires between key reminder switch connector C-59 and battery.
NOTE: After checking joint connector C-57, junction block connectors C-78 and C-84 and intermediate connector C-66, check the wires. If joint connector C-57, junction block connectors C-78 and C-84 and intermediate connector C-66, are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Are the harness wires between key reminder switch connector C-59 and battery in good condition?
YES: There is no action to be taken.
NO: Repair or replace them. The ignition key hole illumination light should work normally.
STEP 10. Check key reminder switch connector C-59 and ETACS-ECU connector C-86 for damage.
Q: Are key reminder switch connector C-59 and ETACS-ECU connector C-86 in good condition?
YES: Go to Step 11.
NO: Repair or replace them. Refer to Harness Connector Inspection. The ignition key hole illumination light should work normally.
STEP 11. Check the harness wire between key reminder switch connector C-59 and ETACS-ECU connector C-86.
NOTE: After checking junction block connectors C-77, check the wires. If junction block connectors C-77, is damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Is the harness wire between key reminder switch connector C-59 and ETACS-ECU connector C-86 in good condition?
YES: There is no action to be taken.
NO: Repair it. The ignition key hole illumination light should work normally.