Inspection Procedure M-1
INSPECTION PROCEDURE M-1: Interior light: Interior light does not work normally.
CIRCUIT OPERATION
Interior lights (dome light and rear personal lights and foot lights and trunk light) are turned on and off by ETACS-ECU. Interior lights are controlled by ETACS-ECU, only when switch position is set to the position 'door controlled operation position'.
TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU operates the interior light automatic shutoff function according to the following switch signals.
- Ignition switch (IG1)
- Key reminder switch
- Driver's or passenger's door switches
- Driver's door lock actuator switch
- Trunk lid latch switch
- Dedicated fuse No. 17 loaded signal If the interior light does not illuminate normally, the relevant input signal circuit or the ETACS-ECU may be defective.
NOTE: If only one the interior lights does not illuminate, the relevant bulb may be burned out or the wiring harness between the defective light and the ETACS-ECU may be defective. In this case, check the relevant circuit by referring to Interior Lights.
TROUBLESHOOTING HINTS
- The key reminder switch may be defective
- The driver's or passenger's door switches be defective
- The driver's door lock actuator switch may be defective
- The trunk lid latch switch 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: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness
STEP 1. Verify the ETACS-ECU power supply circuit.
Check that the hazard warning light illuminate when the ignition switch is in the 'LOCK' (OFF) position.
Q: Does the hazard warning light illuminate?
YES : Go to Step 2
NO : Check the ETACS-ECU battery circuit. Refer to Inspection Procedure P-1. Inspection Procedure P-1
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 and passenger's door switch
- Driver's door lock actuator switch
- Trunk lid latch switch
- Interior light loaded signal
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 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 :
- Scan tool MB991502 does not sound when the ignition switch is turned from "ACC" to "ON": Refer to Inspection Procedure O-2 "The ignition switch (IG1) signal is not sent to the ETACS-ECU." Inspection Procedure O-2
- Scan tool MB991502 does not sound when the ignition key is inserted and then removed: Refer to Inspection Procedure O-3 "The key reminder switch signal is not sent to the ETACS-ECU." Inspection Procedure O-3
- Scan tool MB991502 does not sound when the driver's door is opened: Refer to Inspection Procedure O-8 "The driver's or passenger's door switch signal is not sent to the ETACS-ECU." Inspection Procedure O-8
- Scan tool MB991502 does not sound when the driver's door is unlocked by using the inside lock knob: Refer to Inspection Procedure O-10 "The driver's or passenger's door lock actuator switch signal is not sent to the ETACS-ECU."
- Scan tool MB991502 does not sound when the trunk lid is opened: Refer to Inspection Procedure O-12 "The trunk lid latch switch signal is not sent to the ETACS-ECU." Inspection Procedure O-12
- Scan tool MB991502 does not sound when approximately 30 minutes elapses while the drivers or passenger door is open: Refer to Inspection Procedure O-12 "The trunk lid latch switch signal is not sent to the ETACS-ECU." Inspection Procedure O-12
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 and passenger's door switch
- Driver's door lock actuator switch
- Trunk lid latch switch
- Interior light loaded signal
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 :
- The voltmeter needle does not fluctuate when the ignition switch is turned from "ACC" to "ON": Refer to Inspection Procedure O-2 "The ignition switch (IG1) signal is not sent to the ETACS-ECU." Inspection Procedure O-2
- The voltmeter needle does not fluctuate when the ignition key is inserted and then removed: Refer to Inspection Procedure O-3 "The key reminder switch signal is not sent to the ETACS-ECU." Inspection Procedure O-3
- The voltmeter needle does not fluctuate when the driver's door is opened: Refer to Inspection Procedure O-8 "The driver's or passenger's door switch signal is not sent to the ETACS-ECU." Inspection Procedure O-8
- The voltmeter needle does not fluctuate when the driver's door is unlocked by using the inside lock knob: Refer to Inspection Procedure O-10 "The driver's or passenger's door lock actuator switch signal is not sent to the ETACS-ECU." Inspection Procedure O-10
- The voltmeter needle does not fluctuate when the trunk lid is opened: Refer to Inspection Procedure O-12 "The trunk lid latch switch signal is not sent to the ETACS-ECU." Inspection Procedure O-12
- The voltmeter needle does not fluctuate when the trunk lid is opened: Refer to Inspection Procedure 0-12 "The trunk lid latch switch signal is not sent to the ETACS-ECU." Inspection Procedure O-12
- The voltmeter needle does not fluctuate when approximately 30 minutes elapses while the driver's or passenger's door is open: Refer to Inspection Procedure O-12 "The trunk lid latch switch signal is not sent to the ETACS-ECU." Inspection Procedure O-12
STEP 4. Check the ETACS-ECU connectors C-318 and C-319 and junction block connectors C-301 and C-302 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are ETACS-ECU connectors C-318 and C-319 and junction block connectors C-301 and C-302 in good condition?
YES : Go to Step 5.
NO : Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Diagnostic Aids The interior lights should illuminate normally.
STEP 5. Confirm which one of the interior lights does not illuminate.
If the dome light is integrated with the inside rear view mirror, the mirror assembly built-in circuit makes the dome light illuminate.
Q: Is the dome light integrated in the inside rear view mirror?
YES: Check the power supply line to the inside rear view mirror (by means of the indicator light). Refer to Inside rear view mirror diagnosis?.
NO: Replace the ETACS-ECU. Check that the interior light dim normally.
STEP 5. Check the harness wire betqween ETACS-ECU connectore C-319 and junction block connector C-301 and C-302 in good condition?
YES: replace the ETACS-ECU. The interior lights should illuminate normally.
NO: Repair it. The interior lights should illuminate normally.