Active Skid Control System (ASC)

DTC C1219: Abnormality in steering wheel sensor signal

CAUTION
^ If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
^ When the steering wheel sensor is replaced, always perform calibration to make ASC-ECU learn the neutral point.
^ Do not drop the G and yaw rate sensor or subject it to a shock.
^ When the G and yaw rate sensor is replaced, always perform the calibration to make ASC-ECU learn the neutral point.
^ When the hydraulic unit (integrated with ASC-ECU) is replaced, after turning the ignition switch ON and OFF (vehicle information from ETACS-ECU is registered), always perform the calibration of steering wheel sensor, G and yaw rate sensor, brake fluid pressure sensor, cut valve, and inlet valve.

CIRCUIT OPERATION
Steering wheel sensor outputs the signal to ASC-ECU via CAN bus lines.

DTC SET CONDITIONS
This diagnostic trouble code is set if any malfunction below is found:
^ The tolerance of the neutral position of steering wheel sensor exceeds the specified range.
^ Abnormality in steering wheel sensor output value
^ Abnormality is detected by a comparison of output value from the steering wheel sensor with the output values from wheel speed sensor and G and yaw rate sensor.

PROBABLE CAUSES
^ Improper installation of steering wheel sensor
^ Wheel alignment not performed
^ Steering wheel sensor malfunction
^ Different steering wheel
^ G and yaw rate sensor malfunction
^ Wheel speed sensor malfunction
^ ASC-ECU malfunction
^ External noise interference

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

STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Using scan tool MB991958, diagnose the CAN bus lines.

Q: Is the check result normal?
YES: Go to Step 3.
NO: Repair the CAN bus lines. After repairing the CAN bus line, go to Step 2.

STEP 2. DTC recheck after repairing the CAN bus line

Q: Is DTC C1219 set?
YES: Go to Step 3.
NO: The procedure is complete.

STEP 3. Check the DTC.
Check if the wheel speed sensor-related, G and yaw rate sensor-related, or steering wheel sensor-related diagnostic trouble code is set.

Q: Is any DTC set?
YES: Troubleshoot the relevant diagnostic trouble code, and then go to Step 8.
NO: Go to Step 4.

STEP 4. Check of steering wheel sensor installation status
Check that the steering wheel sensor is installed correctly.

Q: Is the check result normal?
YES: Go to Step 5.
NO: Install the steering wheel sensor correctly. Then go to Step 5.

STEP 5. Wheel alignment check

Q: Is the check result normal?
YES: After checking the wheel alignment, perform the calibration of steering wheel sensor to make ASC-ECU relearn the neutral point. Then go to Step 6.
NO: After adjusting the wheel alignment, perform the calibration of steering wheel sensor to make ASC-ECU relearn the neutral point. Then go to Step 6.

STEP 6. Scan tool service data
Check the following service data.
^ Item 11: Steering angle sensor

Q: Is the check result normal?
YES: Go to Step 7.
NO: Replace the steering wheel sensor. Then go to Step 8.

STEP 7. Check whether the DTC is reset.

Q: Is DTC C1219 set?
YES: Replace the hydraulic unit (incorporates in ASC-ECU). Then go to Step 8.
NO: The procedure is complete.

STEP 8. Check whether the DTC is reset.

Q: Is DTC C1219 set?
YES: Return to Step 1.
NO: The procedure is complete.