DTC C1B0D Solenoid Valve Sub Relay Circuit

DTC detecting condition:

When the vehicle's state is READY ON: When IG1 terminal voltage is 9.5 V or more and the solenoid valve sub relay is commanded ON, the relay contact is in OFF state (BS terminal voltage is less than 3.5 V), and this condition continues for 0.2 seconds or more.
When the vehicle's state is READY OFF: When the solenoid valve sub relay is commanded ON, the relay contact is in OFF state (BS terminal voltage is less than 3.5 V), and this condition continues for 0.2 seconds or more.

Trouble symptom:

Brake warning light illuminates.

Wiring diagram:

Electronic controlled brake system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>ELECTRIC CONTROL BRAKE SYSTEM .

G13245352

Courtesy of SUBARU OF AMERICA, INC.

NOTE: If DTC C1C20 or C1C21 is detected together with DTC C1B0D, perform diagnosis of C1C20 or C1C21 first.

CHECK CONNECTOR .
Check the connecting condition of the EBB control module connector.

Is there looseness, deformation, or corrosion at the connectors?

Yes: Repair or replace the connector.

No: Go to 2.
CHECK EBB CONTROL MODULE .
1. Turn the ignition switch to OFF.
2. Disconnect the EBB control module connector.
3. Measure the voltage between EBB control module connector and chassis ground.
  Connector & terminal
  
  (AD82) No. 10 (+) - Chassis ground (-):
Is the voltage 11 - 14 V?

Yes: Go to 3.

No: Repair or replace the harness.
CHECK DTC .
1. Connect the EBB control module connector.
2. Using the Subaru Select Monitor, perform the clear memory of [Electric Brake Booster]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
3. Turn the ignition switch to OFF.
4. With READY ON, perform a driving test.
5. Read the DTC of [Electric Brake Booster] using the Subaru Select Monitor. Ref. to ELECTRIC BRAKE BOOSTER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC C1B0D displayed?

Yes: Replace the brake booster assembly (with the master cylinder). Ref. to BRAKE>BRAKE BOOSTER .

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