ASC

DTC C1219 Abnormality in steering wheel sensor signal

CAUTION
^ If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ Whenever ECU is replaced, ensure that the CAN bus lines are normal.
^ When the steering wheel sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point.
^ Do not drop or shock the G and yaw rate sensor.
^ When the G and yaw rate sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point.
^ When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor.

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

DTC SET CONDITIONS
This DTC is set if any malfunction below is found:
^ The tolerance of neutral position of steering wheel sensor exceeds the specified range.
^ Abnormality in steering wheel sensor output value
^ When abnormality is detected by comparing the value output from the steering wheel sensor with the one from the wheel speed sensor and the 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
^ Malfunction of wheel speed sensor
^ ASC-ECU malfunction
^ External noise interference
^ Wrong steering wheel is attached

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

STEP 1. M.U.T.-III CAN bus diagnostics
Use scan tool to diagnose the CAN bus lines.

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

STEP 2. DTC recheck after resetting CAN bus lines

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

STEP 3. M.U.T.-III DTC
Check that the wheel speed sensor-related, G and yaw rate sensor-related, or steering wheel sensor-related DTC is set.

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

STEP 4. Check how steering wheel sensor is installed.
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, and then go to Step 5.

STEP 5. Wheel alignment check

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

STEP 6. M.U.T.-III data list
Check the following service data.
^ Item 11: Steering angle sensor

Q: Is the check result normal?
YES: Go to Step 7.
NO: After the steering wheel sensor is replaced, perform the steering wheel sensor calibration to make ASC-ECU learn the neutral point again. Then go to Step 8.

STEP 7. Check whether the DTC is reset.
Drive the vehicle at 12 mph (20 km/h) or more.

NOTE: The ABS warning light does not turn OFF in some cases unless the vehicle runs at 12 mph (20 km/h) or higher.

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

STEP 8. Check whether the DTC is reset.
Drive the vehicle at 12 mph (20 km/h) or more.

NOTE: The ABS warning light does not turn OFF in some cases unless the vehicle runs at 12 mph (20 km/h) or higher.

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