Electronic Time and Alarm Control System (ETACS)
DTC U0126: Steering wheel sensor CAN time-out
CAUTION:
- If DTC U0126 is set to the ETACS-ECU, always diagnose the CAN bus line.
- Before replacing the ECU, ensure that the communication circuit is normal.
TROUBLE JUDGMENT
If the signal from steering wheel sensor cannot be received, the ETACS-ECU sets DTC U0126.
JUDGMENT CRITERIA
After the following statuses continue to be true for 5 seconds, if the communication with the steering wheel sensor cannot be established for 0.6 second or more, the ETACS-ECU determines that a problem has occurred.
- No abnormality is present to the network.
- Ignition switch is in the ON position.
- No abnormality is present to the power supply fuse (IOD fuse), or the odometer value is at 80.5 km (50.0 miles) or more.
- ETACS-ECU system voltage is at 10-16 volts.
TROUBLESHOOTING HINTS
- The steering wheel sensor may be defective.
- The ETACS-ECU may be defective.
- The CAN bus may be defective.
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.
(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) Scan Tool Testing and Procedures."
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the CAN bus line found to be normal?
YES Go to Step 2.
NO Repair the CAN bus line CAN Bus Diagnostics Chart).
STEP 2. Using scan tool MB991958, read the steering wheel sensor diagnostic trouble code.
Check if DTC is set to the steering wheel sensor.
Q. Is the DTC set?
YES Troubleshoot the steering wheel sensor Active Stability Control System (ASC)).
NO Go to Step 3.
STEP 3. Using scan tool MB991958, read the ASC-ECU diagnostic trouble code.
Check if the DTC U0126 is set to the ASC-ECU.
Q. Is the DTC set?
YES Go to Step 4.
NO Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set to the ETACS-ECU.
(1)Erase the DTC.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Replace the steering wheel sensor.
NO The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the steering wheel sensor and the ETACS-ECU How to Cope With Intermittent Malfunctions).
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set to the ETACS-ECU.
(1)Erase the DTC.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Replace the ETACS-ECU.
NO The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the steering wheel sensor and the ETACS-ECU How to Cope With Intermittent Malfunctions).