Inspection Procedure O-10

The ETACS-ECU does not receive any interior light loaded signal.

Interior Light Automatic Shut-Down Function Circuit Part 1:

Interior Light Automatic Shut-Down Function Circuit Part 2:

CIRCUIT OPERATION
The ETACS-ECU operates the following equipment or functions by the interior light loaded signal:
- Interior light automatic shutoff function
- Interior light
- Door-ajar indicator light
- Ignition key cylinder illumination light

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the equipment or functions, which are described in "CIRCUIT OPERATION", do network normally.

TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
- The ETACS-ECU may be defective.

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe




STEP 1. Check ETACS-ECU connector C-226 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-226 in good condition?

YES: Go to Step 2.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the functions or equipment, which are described in "CIRCUIT OPERATION", work normally, the interior light loaded signal should be normal.

STEP 2. Check the battery power supply circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-226.




1. Disconnect ETACS-ECU connector C-226 and measure the voltage available at the junction block side of the connector.




2. Measure the voltage between terminal 20 and ground.
- The voltage should equal approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES: Go to Step 4.

NO: Go to Step 3.










STEP 3. Check the wiring harness between ETACS-ECU connector C-226 (terminal 20) and the battery.

NOTE: Also check junction block connector C-210, joint connector C-05 and intermediate connector C-129 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connector C-210, joint connector C-05 or intermediate C-129 is damaged, Repair or replace the damaged component(s) as described in Harness Connector Inspection.

Q: Is the wiring harness between ETACS-ECU connector C-226 (terminal 20) and the battery 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. If the functions or equipment, which are described in "CIRCUIT OPERATION", work normally the interior light loaded signal should be normal.

STEP 4. Check the ignition switch (IG1) line of the power supply circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-226.




1. Disconnect ETACS-ECU connector C-226 and measure the voltage available at the junction block side of the connector.
2. Turn the ignition switch to the "ON" position.




3. Measure the voltage between terminal 8 and ground.
- The voltage should equal approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES: Go to Step 6.

NO: Go to Step 5.







STEP 5. Check the wiring harness between ETACS-ECU connector C-226 (terminal 8) and the ignition switch (IG1).

NOTE: Also check junction block connector C-211 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connector C-211 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.

Q: Is the wiring harness between ETACS-ECU connector C-226 (terminal 8) and the ignition switch (IG1) 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. If the functions or equipment, which are described in "CIRCUIT OPERATION", work normally, the interior light loaded signal should be normal.

STEP 6. Check the ignition switch (ACC) line of the power supply circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-226.




1. Disconnect ETACS-ECU connector C-226 and measure the voltage available at the junction block side of the connector.
2. Turn the ignition switch to the "ACC" position.




3. Measure the voltage between terminal 4 and ground.
- The voltage should equal approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES: Replace the ETACS-ECU. If the functions or equipment, which are described in "CIRCUIT OPERATION", work normally, the interior light loaded signal should be normal.

NO: Go to Step 7.










STEP 7. Check the wiring harness between ETACS-ECU connector C-226 (terminal 4 and 18) and the ignition switch (ACC).

NOTE: Also check junction block connectors C-210, C-211 and intermediate connector C-129 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connector C-210, C-211 or intermediate C-129 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.

Q: Is the wiring harness between ETACS-ECU connector C-226 (terminal 4 and 18) and ignition switch (ACC) 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. If the functions or equipment, which are described in "CIRCUIT OPERATION", work normally, the interior light loaded signal should be normal.