DTC C139A-00: Brake Pressure Control solenoid Circuit Malfunction; DTC C13D9-00: Brake Pressure Too Low (Brake Booster); DTC C14EC-7E: Brake Pressure Control solenoid "C" Actuator Stuck On [11/2020 - ]: Procedure

Pre-procedure1

• Interview the customer to check the vehicle conditions when the brake system warning light (yellow indicator) illuminated.

• Using the GTS, check for Freeze Frame Data that is recorded when a DTC is stored.

  HINT: 

  Refer to FREEZE FRAME DATA [11/2020 - 12/2023] , or refer to FREEZE FRAME DATA [12/2023 - ]

  Chassis > Brake Booster > Trouble Codes 

  HINT: 

  Freeze Frame Data is only stored once when a DTC is stored.

  Result

  Proceed to
  NEXT

Post-procedure1

• None

Result: 

NEXT 

See step  2

Pre-procedure1

• None

• Clear the DTCs.

  Chassis > Brake Booster > Clear DTCs 

  Chassis > Brake/EPB > Clear DTCs 

  Result

  Proceed to
  NEXT

Post-procedure1

• Turn the ignition switch off.

Result: 

NEXT 

See step  3

Pre-procedure1

• Based on the Freeze Frame Data and interview with the customer, attempt to reproduce the conditions when the malfunction occurred.

• Check if the same DTC is output.

  Chassis > Brake Booster > Trouble Codes 

  Result

  Result	Proceed to
  Only C139A-00, C13D9-00 or C14EC-7E is output	A
  C139A-00, C13D9-00 or C14EC-7E and other DTCs are output	B

Post-procedure1

• None

Result: 

B 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

Result: 

A 

See step  4

1. Check the DTCs that are output.

   Chassis > Brake/EPB > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTCs are output	B

Result: 

B 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

Result: 

A 

See step  5

1. Based on the Freeze Frame Data or interview with the customer, inspect the following items for brake fluid leaks:
   • The brake lines from the brake booster with master cylinder assembly to each wheel cylinder.
   • The main body of the brake booster with master cylinder assembly and brake actuator assembly.

   OK

   There are no fluid leaks.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE APPLICABLE PART 

Result: 

OK 

See step  6

Pre-procedure1

• None

• Clear the DTCs.

  Chassis > Brake Booster > Clear DTCs 

  Chassis > Brake/EPB > Clear DTCs 

  Result

  Proceed to
  NEXT

Post-procedure1

• Turn the ignition switch off.

Result: 

NEXT 

See step  7

HINT: 

Refer to BLEEDING [11/2020 - ]

Result

Result: 

NEXT 

See step  8

Pre-procedure1

• Turn the ignition switch off.

• Make sure that there is no looseness at the locking part and the connecting part of the connectors.

  OK

  The connector is securely connected.

Pre-procedure2

• After 3 minutes elapse after turning the ignition switch off, disconnect the A5 No. 1 skid control ECU (brake booster with master cylinder assembly) connector.

• Check both the connector case and the terminals for deformation and corrosion.

  OK

  No deformation or corrosion.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023]  , or refer to  REMOVAL [12/2023 - ] 

Result: 

OK 

See step  9

Pre-procedure1

• Reconnect the A5 No. 1 skid control ECU (brake booster with master cylinder assembly) connector.

• Measure the voltage and resistance on the wire harness side.

  HINT: 

  Refer to TERMINALS OF ECU [11/2020 - 12/2023] , or refer to TERMINALS OF ECU [12/2023 - ]

  OK

  Voltage and resistance readings are all normal.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  10

Pre-procedure1

• None

• Clear the DTCs.

  Chassis > Brake Booster > Clear DTCs 

  Chassis > Brake/EPB > Clear DTCs 

  Result

  Proceed to
  NEXT

Post-procedure1

• Turn the ignition switch off.

Result: 

NEXT 

See step  11

Pre-procedure1

• Based on the Freeze Frame Data and interview with the customer, attempt to reproduce the conditions when the malfunction occurred.

• Check if the same DTC is output.

  Chassis > Brake Booster > Trouble Codes 

  HINT: 

  If the system returns to normal, it is suspected that a DTC was stored due to a poor connection of a terminal in a connector, air in the system, etc.

  Result

  Result	Proceed to
  C139A-00, C13D9-00 and C14EC-7E are not output	A
  C139A-00, C13D9-00 or C14EC-7E is output	B
  Only C139A-00 is output	C

Post-procedure1

• None

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2020 - ] 

Result: 

B 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023]  , or refer to  REMOVAL [12/2023 - ] 

Result: 

C 

See step  12

1. Check the DTCs that are output.

   Chassis > Brake/EPB > Trouble Codes 

   Result

   Result	Proceed to
   C140A-00 is output	A
   DTCs are not output	B

Result: 

A 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY AND BRAKE ACTUATOR ASSEMBLY 

For Brake Booster with Master Cylinder Assembly: Refer to REMOVAL [11/2020 - 11/2021] , or refer to REMOVAL [11/2021 - 12/2022] , or refer to REMOVAL [12/2022 - 12/2023] , or refer to REMOVAL [12/2023 - ]

For Brake Actuator Assembly: Refer to REMOVAL [11/2020 - 11/2021] , or refer to REMOVAL [11/2021 - 12/2022] , or refer to REMOVAL [12/2022 - 12/2023] , or refer to REMOVAL [12/2023 - ]

Result: 

B 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023]  , or refer to  REMOVAL [12/2023 - ]