DTC U1109: Column SW LIN Timeout: Diagnosis
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
- STEP 1. Check ETACS-ECU connectors C-301, C-317 and column switch connector C-212 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are ETACS-ECU connectors C-301, C-317 and column switch connector C-212 in good condition?
- YES: Go to Step 2.
- NO: Repair or replace the damaged component(s).
- STEP 2. Check the ground circuit to the column switch. Measure the resistance at column switch connector C-212.
- Disconnect column switch connector C-212 and measure the resistance available at the wiring harness side of the connector.
- Measure the resistance value between column switch connector C-212 terminal 4 and ground.
- The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
- YES: Go to Step 4.
- NO: Go to Step 3.
- STEP 3. Check the wiring harness between column switch connector C-212 (terminal 4) and the ground.
- Check the ground wires for open circuit.
Q: Is the wiring harness between column switch connector C-212 (terminal 4) and the ground 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.
- STEP 4. Check the battery power supply circuit to the column switch. Measure the voltage at column switch connector C-212.
- Disconnect column switch connector C-212 measure the voltage available at the wiring harness side of the connector.
- Measure the voltage between column switch connector C-212 terminal 1 and ground.
- The voltage should measure 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-317 (terminal 10) and column switch connector C-212 (terminal 1).
- Check the power supply line (battery supply) for open circuit and short circuit.
Q: Is the wiring harness between ETACS-ECU connector C-317 (terminal 10) and column switch connector C-212 (terminal 1) 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.
- STEP 6. Check the wiring harness between ETACS-ECU connector C-301 (terminal 1) and column switch connector C-212 (terminal 3).
Check the communication lines for open circuit.
Q: Is the wiring harness between ETACS-ECU connector C-301 (terminal 1) and column switch connector C-212 (terminal 3) in good condition?
- YES: Go to Step 7.
- 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 7. Recheck for diagnostic trouble code.
Check again if the DTC is set to the ETACS-ECU.
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) ."
- Erase the DTC.
- Turn the ignition switch to the "ON" position.
- Check if the DTC is set.
- Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
- YES: Replace the lighting switch.
- NO: 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 HOW TO COPE WITH INTERMITTENT MALFUNCTION ).