LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2019 >> Crosstrek Base, Standard Trans >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 5 (Brake Control System (Diagnostics) (HEV)) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC C1811: System
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC C1811: System

WARNING: This page is about a different variant/trim than selected.

DTC detecting condition: 

A fault is detected if VDC control status continues for 15 seconds or more.

Trouble symptom: 

  1. CHECK INSTALLATION OF VDCCM & H/U. 

    Is VDCCM & H/U installed properly without being tilted?

    Is the bracket deformation-free?

    Are the VDCCM & H/U installation bolts installed without missing or getting loose?

    Yes:  Go to  2.

    No:  Repair the defective part.

    Go to  2.

  2. CHECK STEERING WHEEL. 
    1. Drive the vehicle on a flat road.
    2. Park the vehicle straight.
    3. Check the steering wheel for deviation from center.

    Is the deviation from the center of steering wheel less than 5°?

    Yes:  Go to  3.

    No:  Perform the centering adjustment of steering wheel, and perform the VDC sensor midpoint setting mode. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U)>ADJUSTMENT>VDC SENSOR MIDPOINT SETTING MODE .

    Go to  3.

  3. CHECK OUTPUT OF STEERING ANGLE SENSOR USING SUBARU SELECT MONITOR. 
    1. Adjust steering wheel to the center position.
    2. Using Subaru Select Monitor, display [Steering Angle Sensor] of [Data Monitor]. Refer to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DATA MONITOR .

    Is the value of [Steering Angle Sensor] -10° - 10°?

    Yes:  Go to  4.

    No:  Check the installation of the steering wheel and steering angle sensor, and correct the installation if it is improper. If the installation condition is correct, replace the sensor.

  4. CHECK OUTPUT OF SENSORS USING SUBARU SELECT MONITOR. 
    1. Drive the vehicle on a flat road.
    2. Park the vehicle straight.
    3. Using Subaru Select Monitor, display [Lateral G Sensor], [Longitudinal G Sensor], and [Yaw Rate Sensor] of [Data Monitor]. Refer to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DATA MONITOR .

    Is the reading of each sensor following value?

    [Lateral G Sensor]: -2 - 2 m/s2

    [Longitudinal G Sensor]: -2 - 2 m/s2

    [Yaw Rate Sensor]: -4 - 4 deg/s

    Yes:  Go to  5.

    No:  Recheck from step 1, and if the problem is not solved, Go to  8.

  5. SET 0 POINT SETTING OF LONGITUDINAL G SENSOR USING SUBARU SELECT MONITOR. 
    1. Select the [Work Support] using Subaru Select Monitor. Refer to BRAKE CONTROL (DIAGNOSTICS) (HEV)>WORK SUPPORT .
    2. Perform the VDC sensor midpoint setting mode. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U)>ADJUSTMENT>VDC SENSOR MIDPOINT SETTING MODE .

    Is 0 point setting successful?

    Yes:  Go to  6.

    No:  Recheck from step 1, and when the 0 point setting is not possible, replace the VDCCM & H/U and steering angle sensor. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) . Refer to VEHICLE DYNAMICS CONTROL (VDC)>STEERING ANGLE SENSOR .

  6. PERFORM DRIVING TEST. 

    Execute the inspection mode. Refer to BRAKE CONTROL (DIAGNOSTICS) (HEV)>INSPECTION MODE .

    Does the ABS warning light or VDC warning light illuminate during driving?

    Does ABS or VDC operate abnormally?

    Yes:  Recheck from step 1, and when the warning lights illuminate or improperly operate, replace the VDCCM & H/U. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .

    No:  Go to  7.

  7. CHECK OUTPUT OF SENSORS USING SUBARU SELECT MONITOR. 
    1. Park the vehicle on a level surface.
    2. Using Subaru Select Monitor, display [Lateral G Sensor], [Longitudinal G Sensor], and [Yaw Rate Sensor] of [Data Monitor]. Refer to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DATA MONITOR .

    Is the reading of each sensor following value?

    [Lateral G Sensor]: -2 - 2 m/s2

    [Longitudinal G Sensor]: -2 - 2 m/s2

    [Yaw Rate Sensor]: -4 - 4 deg/s

    Yes:  Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.

    No:  Replace the VDCCM & H/U. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .

  8. CHECK OUTPUT OF SENSORS USING SUBARU SELECT MONITOR. 
    1. Remove the VDCCM & H/U installation bolt and bracket.
    2. Keep VDCCM & H/U in a horizontal position.
    3. Using Subaru Select Monitor, display [Lateral G Sensor], [Longitudinal G Sensor], and [Yaw Rate Sensor] of [Data Monitor]. Refer to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DATA MONITOR .

    When VDCCM & H/U is in a horizontal position, is the reading of each sensor following value?

    [Lateral G Sensor]: -1.5 - 1.5 m/s2

    [Longitudinal G Sensor]: -1.5 - 1.5 m/s2

    [Yaw Rate Sensor]: -4 - 4 deg/s

    Yes:  Check the bracket and brake pipe, and install VDCCM & H/U in a horizontal position to the vehicle.

    No:  Replace the VDCCM & H/U. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .

scientia non olet · About LEMON Manuals