LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2013 >> Outback Base, Standard Trans >> Repair and Diagnosis >> Brakes >> Traction Control >> Vehicle Dynamics Control (VDC) System (Diagnostics) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC C0027 Rear Left Abs Sensor Circuit Open Or Short >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

DIAGNOSTIC PROCEDURE

Step Check Yes No
1 CHECK POOR CONTACT OF CONNECTOR. 
Check if there is poor contact between VDCCM&H/U and ABS wheel speed sensor.		 Is there poor contact? Repair the connector. Go to step 2  .
2 CHECK HARNESS CONNECTOR BETWEEN VDCCM&H/U AND ABS WHEEL SPEED SENSOR. 
  1. Disconnect the connector (B310) from the VDCCM&H/U.
  2. Disconnect the connector from ABS wheel speed sensor.
  3. Measure the resistance between VDCCM&H/U connector and ABS wheel speed sensor connector.

    Connector & terminal 

    DTC C0021 

    (B310) No. 18 - (B6) No. 1: 

    (B310) No. 19 - (B6) No. 2: 

    DTC C0023 

    (B310) No. 22 - (B15) No. 1: 

    (B310) No. 21 - (B15) No. 2: 

    DTC C0025 

    (B310) No. 25 - (R72) No. 1: 

    (B310) No. 24 - (R72) No. 2: 

    DTC C0027 

    (B310) No. 15 - (R73) No. 1: 

    (B310) No. 16 - (R73) No. 2: 

 Is the resistance less than 1 Ω? Go to step 3  . Repair the harness connector between VDCCM&H/U and ABS wheel speed sensor.
3 CHECK GROUND SHORT OF HARNESS. 
Measure the resistance between VDCCM&H/U connector and chassis ground.
Connector & terminal 
DTC C0021 
(B310) No. 19 - Chassis ground: 
DTC C0023 
(B310) No. 21 - Chassis ground: 
DTC C0025 
(B310) No. 25 - Chassis ground: 
DTC C0027 
(B310) No. 15 - Chassis ground: 		 Is the resistance 1 MΩ or more? Go to step 4  . Repair the harness connector between VDCCM&H/U and ABS wheel speed sensor.
4 CHECK ABS WHEEL SPEED SENSOR POWER SUPPLY CIRCUIT. 
  1. Connect the VDCCM&H/U connector.
  2. Turn the ignition switch to ON.
  3. Measure the voltage between ABS wheel speed sensor connector and chassis ground.

    Connector & terminal 

    DTC C0021 

    (B6) No. 1 (+) - Chassis ground (-): 

    DTC C0023 

    (B15) No. 1 (+) - Chassis ground (-): 

    DTC C0025 

    (R72) No. 2 (+) - Chassis ground (-): 

    DTC C0027 

    (R73) No. 2 (+) - Chassis ground (-): 

 Is the voltage 5 - 16 V? Go to step 6  . Go to step 5  .
5 CHECK VDCCM&H/U POWER SUPPLY CIRCUIT. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the VDCCM&H/U connector.
  3. Turn the ignition switch to ON.
  4. Measure the voltage between VDCCM&H/U connector terminals.

    Connector & terminal 

    (B310) No. 7 (+) - (B310) No. 13 (-): 

    (B310) No. 14 (+) - (B310) No. 13 (-): 

    (B310) No. 1 (+) - (B310) No. 13 (-): 

 Is the voltage 10 - 15 V? Go to step 6  . Check the generator, battery and VDCCM&H/U power supply circuit.
6 CHECK ABS WHEEL SPEED SENSOR SIGNAL. 
  1. Install the ABS wheel speed sensor.
  2. Prepare an oscilloscope.
  3. Check the ABS wheel speed sensor. < Refer to CHECK ABS WHEEL SPEED SENSOR UNIT , INSPECTION, Front ABS Wheel Speed Sensor. >
 Does the oscilloscope indicate the waveform pattern as shown in the figure? Go to step 7  . Replace the ABS wheel speed sensor. < Refer to FRONT ABS WHEEL SPEED SENSOR . >
7 CHECK VDCCM&H/U. 
  1. Connect all connectors.
  2. Clear the memory. < Refer to CLEAR MEMORY MODE . >
  3. Perform the Inspection Mode. < Refer to INSPECTION MODE . >
  4. Read the DTC.
 Is the same DTC displayed? Replace the VDCCM&H/U. < Refer to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U) . > Go to step 8  .
8 CHECK OTHER DTC DETECTION.  Is any other DTC displayed? Perform the diagnosis according to DTC. < Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . > It results from a temporary noise interference.
scientia non olet · About LEMON Manuals