DTC C1400-00: Brake Pressure Leak Malfunction; DTC C140A-00: Pressure Control Reservoir Leak Malfunction [12/2019 - ]: Procedure

1. Mount a pedal effort gauge.
2. Disconnect the A9 brake booster with accumulator pump assembly connector.
3. Depress the brake pedal 10 times or more until it becomes hard.

   HINT: 

   Depressing the brake pedal with the connector of the brake booster with accumulator pump assembly disconnected drops the accumulator pressure to approximately 0 MPa.

4. Connect an LSPV gauge set.
5. Slowly depress the brake pedal and check the wheel cylinder pressure with respect to brake pedal depression force.
   NOTE:

   Check the wheel cylinder pressure with the switching solenoid (SSA, SGH) off and an accumulator pressure of 0 MPa.

   Standard Pressure

   FOR FRONT RIGHT WHEEL
   
   

   Brake Effort [N (kgf, lbf)]	Hydraulic Pressure [MPa (kgf/cm2 , psi)]
   200 (20, 45.0)	0.00 to 2.88 (0.0 to 29.4, 0 to 418)
   500 (51, 112.4)	1.13 to 5.13 (11.5 to 52.3, 164 to 744)

   FOR REAR RIGHT WHEEL
   
   

   Brake Effort [N (kgf, lbf)]	Hydraulic Pressure [MPa (kgf/cm2 , psi)]
   200 (20, 45.0)	0.00 to 2.88 (0.0 to 29.4, 0 to 418)
   500 (51, 112.4)	1.13 to 5.13 (11.5 to 52.3, 164 to 744)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  4

Result: 

OK 

See step  2

1. Clear the DTCs.

   Chassis > Brake Booster > Clear DTCs 

   Chassis > Brake/EPB > Clear DTCs 

2. Turn the ignition switch off.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  3

1. Based on the Freeze Frame Data and interview with the customer, attempt to reproduce the conditions when the malfunction occurred.
2. Check if the same DTC is output.

   Chassis > Brake Booster > Trouble Codes 

   Chassis > Brake/EPB > Trouble Codes 

   Result

   Result	Proceed to
   DTCs C1400-00 and C140A-00 are not output.	A
   DTCs C1400-00 and/or C140A-00 are output.	B
   DTC C140A-00 and C139A-00 are output at the same time.	C

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023]  , or refer to  REMOVAL [11/2023 - ] 

Result: 

C 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY AND BRAKE ACTUATOR ASSEMBLY 

for Brake Booster with Master Cylinder Assembly: Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023] , or refer to REMOVAL [11/2023 - ]

for Brake Actuator Assembly: Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023] , or refer to REMOVAL [11/2023 - ]

1. Brake fluid leaks and air in brake line inspection
   1. Check and take a note of the fluid level in the brake master cylinder reservoir assembly.
   2. Repeatedly depress the brake pedal and confirm that the brake pedal feels normal (no air in the system, etc.).
   3. Check if the brake fluid level in the brake master cylinder reservoir assembly has changed.
   4. If the brake fluid level has decreased, check for leaks due to damaged brake lines or hoses, loose union nuts, damaged brake master cylinder assembly seals, etc.

   OK

   There are no brake fluid leaks and no air in the system.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023]  , or refer to  REMOVAL [11/2023 - ] 

Result: 

NG 

REPAIR BRAKE FLUID LEAKS AND ADD FLUID