Inspection Procedure M-6
Interior Light: The ignition key hole illumination light does not illuminate or go out normally.Ignition Key Hole Illumination Light Circuit:
NOTE: This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor." How To Use SWS Monitor
CIRCUIT OPERATION
- When the driver's door is opened with the ignition switch at "ACC" position, the ETACS-ECU illuminates the ignition key hole illumination light.
- The ignition key hole illumination light goes out in 30 seconds after the driver's door is closed. The ignition key hole illumination light remains illuminated for 30 seconds after the ignition key is pulled out.
- The ETACS-ECU operates the ignition key hole illumination light according to the input signals from the following switches:
- Ignition switch (IG1): OFF
- Key reminder switch: OFF
- Vehicle condition
- Ignition switch: ACC position
- Ignition key is inserted in the ignition key cylinder
TECHNICAL DESCRIPTION (COMMENT)
Is the ignition key hole illumination light does not illuminate, the input circuits from the switches described in "CIRCUIT OPERATION", the key reminder switch (ignition key hole illumination light bulb) or the ETACS-ECU may be defective.
TROUBLESHOOTING HINTS
- The driver's door switch may be defective
- The key reminder switch (key reminder switch or ignition key hole illumination light bulb) may be defective
- The ETACS-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
- MB991813: SWS Monitor Kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: Probe Harness
- MB991854: SWS Monitor Harness (For 13-pin)
STEP 1. Use scan tool MB991958 to select "ECU COMM CHK" on the SWS monitor display.
Check the ETACS-ECU.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector (16-pin).
2. Connect SWS monitor harness MB991854 to the data link connector (13-pin).
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Operate the scan tool MB991958 according to the procedure below to display "ECU COMM CHECK."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "ECU COMM CHK".
5. Scan tool MB991958 should show "OK" on the "ECU COMM CHK" menu for the "ETACS ECU" menu.
Q: Is "OK" displayed on the "ETACS ECU" menu?
YES: Go to Step 2.
NO: Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible."
STEP 2. Check the input signal by using "DATA LIST" menu of the SWS monitor.
Check the input signals from the switches in the following conditions:
- Turn the ignition switch to the "OFF" position.
- Open the driver's door. (The front door switch (LH) is turned to the ON position.)
- Close the front passenger's door. (The front door switch (RH) is turned to the OFF position.)
1. Operate the scan tool MB991958 according to the procedure below to display "ETACS ECU."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "SWS MONITOR."
d. Select "DATA LIST."
e. Select "ETACS ECU."
2. Check that normal conditions are displayed on the items described in the table.
Q: Are normal conditions displayed on the "IG SW (IG1)" and "FRONT DOOR SW"?
YES
NO
NO
STEP 3. Check the input signal (by using the pulse checking mode of the monitor).
Check the input signals from the key reminder switch.
1. Operate the scan tool MB991958 according to the procedure below to display "PULSE CHECK."
a. Select "SYSTEM SELECT."
b. Select "SWS."
c. Select "PULSE CHECK."
2. Check whether scan tool MB991958 sounds or not when the ignition key is removed and reinserted.
Q: Does scan tool MB991958 sound when the ignition key is removed and reinserted?
YES: Go to Step 4.
NO: Refer to Inspection Procedure O-1 "ETACS-ECU does not receive any signal from the key reminder switch."
STEP 4. Check ETACS-ECU connector C-219 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-219 in good condition?
YES: Go to Step 5.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the ignition key hole illumination light illuminates normally.
STEP 5. Check at ETACS-ECU connector C-219 in order to check the line from the ignition key hole illumination light.
1. Disconnect ETACS-ECU connector D-219, and measure at the wiring harness side.
2. Connect terminal 69 to ground.
Q: Does the ignition key hole illumination light illuminate?
YES: Replace the ETACS-ECU. Verify that the ignition key hole illumination light illuminates normally.
NO: Go to Step 6.
STEP 6. Check the ignition key hole illumination light bulb.
Q: Is the ignition key hole illumination light bulb in good condition?
YES: Go to Step 7.
NO: Replace the bulb. Verify that the ignition key hole illumination light illuminates normally.
STEP 7. Check key reminder switch connector C-304 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is key reminder switch connector C-304 in good condition?
YES: Go to Step 8.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the ignition key hole illumination light illuminates normally.
STEP 8. Check the key reminder switch (ignition key hole illumination).
1. Disconnect key reminder switch connector C-304.
2. Remove the ignition key hole illumination light bulb. Then measure the resistance value between the bulb terminals.
3). Install a bulb to the key remainder switch, and measure the resistance between connector C-304 terminal 1 and 2. The measured resistance value should be roughly the same as the value measured in Step (2).
Q: Are these two resistance values extremely different?
YES: Replace the key reminder switch. Verify that the ignition key hole illumination light illuminates normally.
NO: (roughly the same) : Go to Step 9.
STEP 9. Check the battery power supply circuit to the key reminder switch. Measure the resistance at key reminder switch connector C-304.
1. Disconnect key reminder switch connector C-304 and measure at the voltage available at the wiring harness side of the connector.
2. Measure the voltage between terminal 2 and ground.
- The voltage should be approximately 12 volts (battery positive voltage).
Q: Is the measured voltage approximately 12 volts (battery positive voltage)?
YES: Go to Step 11.
NO: Go to Step 10.
STEP 10. Check the wiring harness between key reminder switch connector C-304 (terminal 2) and ETACS-ECU connector C-219 (terminal 71).
Q: Is the wiring harness between key reminder switch connector C-304 (terminal 2) and ETACS-ECU connector C-219 (terminal 71) in good condition?
YES: No action is necessary and testing is complete.
NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the ignition key hole illumination light illuminates normally.
STEP 11. Check the wiring harness between key reminder switch connector C-304 (terminal 1) and ETACS-ECU connector C-219 (terminal 69).
Q: Is the wiring harness between key reminder switch connector C-304 (terminal 1) and ETACS-ECU connector C-219 (terminal 69) in good condition?
YES: No action is necessary and testing is complete.
NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the ignition key hole illumination light illuminates normally.