STEP 1. Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code.
STEP 2. Check ETACS-ECU connectors C-416 and C-417 and lighting control sensor connector E-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
STEP 3. Check the ground circuit to the lighting control sensor. Measure the resistance at lighting control sensor connector E-08.
STEP 4. Check the wiring harness between lighting control sensor connector E-08 (terminal 3) and the ground.
- Check the ground wires for open circuit.
Is the wiring harness between lighting control sensor connector E-08 (terminal 3) and the ground in good condition?
No action is necessary and testing is complete. 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 5. Check the battery power supply circuit to the lighting control sensor. Measure the voltage at lighting control sensor connector E-08.
STEP 6. Check the wiring harness between ETACS-ECU connector C-417 (terminal 10) and lighting control sensor connector E-08 (terminal 1).
STEP 7. Check the wiring harness between ETACS-ECU connector C-416 (terminal 1) and lighting control sensor connector E-08 (terminal 2).
STEP 8. Recheck for diagnostic trouble code.
Check again if the DTC is set in the ETACS-ECU.(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 the Scan Tool (M.U.T.-III)
."
(2) Erase the DTC.
(3) Turn the ignition switch to the "ON" position.
(4) Check if the DTC is set.
(5) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Replace the lighting control sensor. A poor connection, open circuit or other intermittent malfunction is present in the LIN bus lines between the lighting control sensor and the ETACS-ECU (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).