C1344

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1341/62-C1344/65: 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 inputs the operating fluid pressure of each wheel cylinder using the wheel cylinder pressure sensors in order to control the braking force of each wheel.
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

If DTCs are output, perform a DTC clear Reading and Clearing Diagnostic Trouble Codes.






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
When replacing the brake actuator, perform initialization of linear solenoid valve and calibration Programming and Relearning.
HINT: When C1364/61 is output together with C1341/62, C1342/63, C1343/64 and 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 from the front and rear brake systems Service and Repair.
NEXT -- Continue to next step.
3. CHECK WIRE HARNESS (SKID CONTROL ECU - BODY GROUND)




(a) Disconnect the A13 and A15 ECU connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. READ VALUE USING TECHSTREAM (WHEEL CYLINDER PRESSURE SENSOR)
(a) Connect the pedal effort gauge.
(b) Install the LSPV gauge (SST) and perform bleeding Service and Repair.
SST: 09709-29018
(c) Connect the Techstream to the DLC3.
(d) Select the Data List mode on the Techstream.

ABS / VSC / TRAC:





(e) Check the output value of the wheel cylinder pressure at each fluid pressure during the electronically controlled brake system control.
Standard voltage:
Front wheel cylinder pressure sensor





Rear wheel cylinder pressure sensor





NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.
5. 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 system control.
- If the brake pedal stroke sensor connector is disconnected, the fail-safe function will prohibit electronically controlled brake system control.
- As the Active Test does not prohibit electronically controlled brake system control when the vehicle is running, disconnect the stroke sensor connector, and then carry out the inspection.
- Disc wear can be checked by measuring the disc thickness.

NG -- REPLACE BRAKE DISC
OK -- Continue to next step.
6. RECONFIRM DTC
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Repeat the braking test under malfunction conditions recreated based on the Freeze Frame Data Freeze Frame Data.
(c) Check if the same DTCs are recorded Reading and Clearing Diagnostic Trouble Codes.
HINT: Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result





B -- REPLACE BRAKE ACTUATOR ASSEMBLY
A -- END