DTC C1983: High Frequency Operation

DTC detecting condition: 

This malfunction is stored if the electronic parking brake is operated with high frequency in a short period of time.

Trouble symptom: 

Parking brake system does not operate sometimes.

Failure detection pattern: 

• "Primary" (high-priority diagnosis)

Warning light/indicator light: 

The combination of DTC and warning light display may differ from the list depending on vehicle conditions and driving conditions at the time of failure detection.

• ABS warning light -
• VDC warning light & VDC operation indicator light -
• Electronic parking brake warning light (red)
• Brake warning light (EBD warning light) (red) -

1. CHECK OUTPUT OF AMBIENT SENSOR USING SUBARU SELECT MONITOR  .

   Using the Subaru Select Monitor, read data of [Ambient Temp Sensor] in the [Data Monitor] of [Brake Control]. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DATA MONITOR .

   Is the reading of [Ambient Temp Sensor] within the range of ±10°C (50°F) to the ambient temperature?

   Yes:  GO TO  2.

   No:  Repair the ambient sensor circuit.

2. CHECK VDCCM & H/U  .
   1. Turn the ignition switch to OFF.
   2. Stop the vehicle for approximately one hour.
   3. Using the Subaru Select Monitor, perform the clear memory of [Brake Control]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY .
   4. Execute the inspection mode. Ref. to BRAKE CONTROL (DIAGNOSTICS)>INSPECTION MODE .
   5. Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is the same DTC displayed?

   Yes:  Replace the VDCCM & H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .

   No:  GO TO  3.

3. CHECK DETECTION OF OTHER DTCS FOR VDC  .

   Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is any other DTC displayed?

   Yes:  Perform the diagnosis according to the DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.