Inspection Procedure 1
Inspection Procedure 1: The sunshade illumination does not illuminate.
CAUTION:
Whenever the ECU is replaced, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
TECHNICAL DESCRIPTION (COMMENT)
With the ignition switch turned to the ACC or ON position, if the sunshade illumination does not illuminate at all, the sunshade illumination changeover switch, ETACS-ECU, wiring harness, or connector may have a problem. When the sunshade illumination changeover switch is set to
"OFF", the sunshade illumination will not illuminate. Therefore, check that the switch is not set to "OFF".
TROUBLESHOOTING HINTS
- Malfunction of the sunshade illumination changeover switch
- Malfunction of the ETACS-ECU
- Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
STEP 1. Sunshade illumination operation check
Set the ignition switch to the ACC position, and then check that the sunshade illumination turns ON when the sunshade illumination changeover switch is pressed.
Q. Is the check result normal?
YES The diagnosis is complete.
NO Got to Step 2.
STEP 2. Front dome light operation check
Check if the front dome light illuminates and goes out normally.
Q. Is the check result normal?
YES Go to Step 3.
NO Refer to Inspection Procedure "The front dome light does not illuminate normally" Inspection Procedure 1.
STEP 3. Using scan tool MB991958, read the diagnostic trouble code.
(1)
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.
Connect scan tool MB991958. Refer to "How to connect scan too (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."
(2)Turn the ignition switch to the "ON" position.
(3)Check whether the ETACS-ECU related DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Diagnose the ETACS-ECU. Refer to ETACS, Diagnosis Electronic Time and Alarm Control System (ETACS).
NO Go to Step 4.
STEP 4. Using scan tool MB991958, check data list
Check the input signal from the ignition switch (ACC) in ETACS-ECU.
- Turn the ignition switch to the ACC position.
OK: Normal condition is displayed
Q. Is the check result normal?
YES Go to Step 5.
NO : Troubleshoot the ETACS-ECU. Refer to ETACS, Diagnosis Symptom Chart.
STEP 5. Check ETACS-ECU connector C-411 and C-415, sunshade illumination changeover switch connector E-12, intermediate connector E-14 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q. Is ETACS-ECU connector C-411 and C-415, sunshade illumination changeover switch connector E-12, intermediate connector E-14 in good condition?
YES Go to Step 6.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 6. Resistance measurement at the E-14 intermediate connector
(1)Disconnect the connector, and measure at the ground side.
(2)Measure the resistance between the E-14 intermediate connector terminal No. 3 and the body ground.
OK: The measured value should be continuity exists (2 ohms or less).
Q. Is the measured resistance 2 ohms or less?
YES Go to Step 8.
NO Go to Step 7.
STEP 7. Check the wiring harness between the intermediate connector E-14 terminal No. 3 and the ground
- Check the ground wires for open circuit.
Q. Is the wiring harness between the intermediate connector E-14 terminal No. 3 and ground in good condition?
YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
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.
STEP 8. Check the wiring harness between ETACS-ECU connector C-415 terminal No. 18 and the intermediate connector E-14 terminal No. 4
NOTE:
Also check intermediate connector C-226 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-226 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.
- Check the power supply lines for open and short circuit.
Q. Is the wiring harness between ETACS-ECU connector C-415 terminal No. 18 and the intermediate connector E-14 terminal No. 4 in good condition?
YES Go to Step 9.
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.
STEP 9. Check of sunshade illumination changeover switch
Check the sunshade illumination changeover switch. Refer to Component Tests and General Diagnostics.
Q. Is the check result normal?
YES Go to Step 10.
NO Replace the sunshade illumination changeover switch.
STEP 10. Resistance measurement at the E-12 sunshade illumination changeover switch connector
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the E-12 sunshade illumination changeover switch connector terminal No. 1 and the body ground.
OK: The measured value should be continuity exists (2 ohms or less).
Q. Is the measured resistance 2 ohms or less?
YES Go to Step 12.
NO Go to Step 11.
STEP 11. Check the wiring harness between the sunshade illumination changeover switch connector E-12 terminal No. 1 and the ground
- Check the ground wires for open circuit.
Q. Is the wiring harness between sunshade illumination changeover switch connector E-12 terminal No. 1 and ground in good condition?
YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
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.
STEP 12. Check the wiring harness between ETACS-ECU connector C-411 terminal No. 17 and sunshade illumination changeover switch connector E-12 terminal No. 2
NOTE:
Also check intermediate connector C-226 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-226 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.
- Check the power supply lines for open and short circuit.
Q. Is the wiring harness between ETACS-ECU connector C-411 terminal No. 17 and sunshade illumination changeover switch connector E-12 terminal No. 2 in good condition?
YES Go to Step 13.
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.
STEP 13. Retest the system
Set the ignition switch to the ACC position, and then check that the sunshade illumination turns ON when the sunshade illumination changeover switch is pressed.
Q. Do the sunshade illumination work normal?
YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Replace the ETACS-ECU.