Combination Meter Assembly
DTC U1109: ETACS-ECU Time-outCAUTION:
- If DTC U1109 is set in the combination meter, diagnose the CAN main bus line.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
NOTE: When the DTC relating to the CAN communication error are set, make sure of the vehicle equipment. When the vehicle is not equipped with the system the combination meter communicates to, the DTC is always set. This is not abnormal.
CIRCUIT OPERATION
The ETACS-ECU communicates with the combination meter and the powertrain control module via CAN bus line to obtain necessary information. Both the combination meter and the powertrain control module have terminator resistors.
DTC SET CONDITION
The combination meter receives signal from the
ETACS-ECU via CAN bus lines. If it can not receive all the necessary signals from the ETACS-ECU, DTC U1109 is set.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
- Connector(s) or wiring harness in the CAN bus lines between the ETACS-ECU and the combination meter, the power supply system to the ETACS-ECU, the ETACS-ECU itself, or the combination meter may be defective.
Past trouble
- Carry out diagnosis with particular emphasis on connector(s) or wiring harness in the CAN bus lines between the ETACS-ECU and the combination meter, and the power supply system to the ETACS-ECU.
NOTE: For a past trouble, you may not find it by the M.U.T.-III CAN bus diagnostics even if there is any failure in CAN bus lines. In this case, check the CAN bus lines. You can narrow down the possible cause of the trouble by referring to the DTC, which is set regarding the CAN communication-linked ECUs. (Refer to CAN bus line Diagnostics Flow. Explanation About the Scan Tool (M.U.T.-III) CAN Bus Diagnostics
TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- Malfunction of ETACS-ECU
- Malfunction of combination meter (incorporating ECU)
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle 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. Using scan tool MB991958, diagnose the CAN bus line.
Use scan tool MB991958 to diagnose the CAN bus lines.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Diagnose the CAN bus line.
Q: Is the check result satisfactory?
YES : Go to Step 2.
NO : Repair the CAN bus lines. On completion, go to Step 4.
STEP 2. Using scan tool, MB991958, read the ETACS-ECU diagnostic trouble code.
Check that the ETACS-ECU sets a DTC.
Q: Is the DTC set?
YES : Diagnose the SWS system Diagnostic Trouble Code Descriptions.
NO : Go to Step 3.
STEP 3. Using scan tool MB991958, read the multi-center display diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked systems below, is set.
- Multi-center display
DTC 019: ETACS-ECU time-out
Q: Is the DTC set?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the DTC set?
YES : Replace ETACS-ECU and then go to step 6.
NO : A poor connection, open circuit or other intermittent malfunction is present in the lines between the ETACS-ECU and the combination meter.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the DTC set?
YES : Replace combination meter and then go to step 6.
NO : A poor connection, open circuit or other intermittent malfunction is present in the lines between the ETACS-ECU and the combination meter.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 1.
NO : The procedure is complete.