STEP 1. Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code.
STEP 2. Check ETACS-ECU connectors C-411 and C-417 and column switch connector C-314 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
STEP 3. Check the ground circuit to the column switch. Measure the resistance at column switch connector C-314.
STEP 4. Check the wiring harness between column switch connector C-314 (terminal 4) and the ground.
STEP 5. Check the battery power supply circuit to the column switch. Measure the voltage at column switch connector C-314.
STEP 6. Check the wiring harness between ETACS-ECU connector C-417 (terminal 10) and column switch connector C-314 (terminal 1).
- Check the power supply line (battery supply) for open circuit and short circuit.
Is the wiring harness between ETACS-ECU connector C-417 (terminal 10) and column switch connector C-314 (terminal 1) 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 7. Check the wiring harness between ETACS-ECU connector C-411 (terminal 1) and column switch connector C-314 (terminal 3).
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 column switch assembly. A poor connection, open circuit or other intermittent malfunction is present in the LIN bus lines between the column switch and the ETACS-ECU (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).