C1344

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1341/62: Front Hydraulic System RH Malfunction

DTC C1341/62 - Front Hydraulic System RH Malfunction

DTC C1342/63 - Front Hydraulic System LH Malfunction

DTC C1343/64 - Rear Hydraulic System RH Malfunction

DTC C1344/65 - Rear Hydraulic System LH Malfunction

DESCRIPTION

The skid control ECU controls braking force according to the hybrid system regenerative braking force and inputs the fluid pressure necessary for operating each wheel cylinder according to the wheel cylinder pressure sensor.
DTCs may be stored if one of the following occurs:

- Brake fluid leaks
- Wheel cylinder vibrates due to uneven wear of brake disc rotor
- Foreign matter enters solenoid valve
- Line pressure drops during air bleeding
- Disc brake pad is replaced
- Rotor is replaced

WIRING DIAGRAM

INSPECTION PROCEDURE
NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.
HINT: When C1364/61 is output together with C1341/62, C1342/63, C1343/64 or C1344/65, inspect and repair the trouble areas indicated by C1364/61 first.

PROCEDURE

1. CHECK BRAKE FLUID LEAKAGE
(a) Check that there is no fluid leakage in the brake line between the brake actuator and the wheel cylinder which is the cause of DTCs.
(b) Check that the brake is not dragging.
OK:
There is no fluid leakage or dragging.
NG -- REPAIR OR REPLACE APPLICABLE PART
OK -- Continue to next step.
2. PERFORM AIR BLEED
(a) Bleed the air out of the front and rear systems Service and Repair.
NEXT -- Continue to next step.
3. RECONFIRM DTC
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Turn the ignition switch on.
(c) Check the same DTCs are recorded Reading and Clearing Diagnostic Trouble Codes.
Result:

HINT: DTC may be stored if foreign matter or air enters the solenoid valve.

B -- END
A -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (BETWEEN SKID CONTROL ECU AND BRAKE ACTUATOR ASSEMBLY)
(a) Disconnect the skid control ECU connectors and brake actuator connector.

(b) Measure the resistance according to the value(s) in the table below.
Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. READ VALUE OF TECHSTREAM (WHEEL CYLINDER PRESSURE SENSOR)
(a) Connect the pedal effort gauge.
(b) Install the LSPV gauge (SST) and bleed air On-Vehicle Inspection.
SST: 09709-29018
(c) Connect Techstream to the DLC3.
(d) Select the Data List mode on Techstream.

ABS / VSC / TRAC:

(e) Check the output value of the wheel cylinder pressure at each fluid pressure during the Electronically Controlled Brake control.
Voltage:
Front wheel cylinder pressure sensor

Rear wheel cylinder pressure sensor

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.
6. CHECK BRAKE DISC
(a) Disconnect the brake pedal stroke sensor connector.
(b) Carry out the running and braking test according to freeze frame data or customer problem analysis. Check the brake line pressure vibration caused due to uneven wear of the disc according to brake pedal vibration.
OK:
Brake pedal does not vibrate during braking.
HINT:
- The brake pedal does not kick back due to wheel cylinder piston vibration during Electronically Controlled Brake control.
- If the brake pedal stroke sensor connector is disconnected, the fail-safe function prohibits Electronically Controlled Brake control.
- The Active Test does not prohibit Electronically Controlled Brake control when the vehicle is running, so disconnect the stroke sensor connector and carry out inspection.
- Disc wear can be checked by measuring the disc thickness.

NG -- REPLACE BRAKE DISC
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY