Hydraulic Control System Malfunction
BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1214/62: Hydraulic Control System Malfunction
C1214/62 - Hydraulic Control System Malfunction
DESCRIPTION
The skid control ECU controls braking force according to the hybrid control system regenerative braking force and inputs the hydraulic 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 a brake disc.
* Foreign matter enters solenoid valve.
* Line pressure drops during air bleeding.
* Brake pad is replaced.
* Rotor is replaced.
HINT
When replacing the brake pad, retracting the brake calipers piston and attaching a new brake pad will greatly increase the clearance between the brake pad and brake disc, which will likely cause these DTCs to be set the next time the brake pedal is depressed. As there is not malfunction, clear the DTCs.
INSPECTION PROCEDURE
NOTICE:
When replacing the brake booster with master cylinder (brake actuator), perform initialization and calibration of the linear solenoid valve Initialization.
HINT
When C1364/61 is output together with C1214/62, inspect and repair the trouble areas indicated by C1364/61 first C1246.
PROCEDURE
1. CHECK FOR FLUID LEAK
(a) Check that there is no fluid leaks in the brake line between the brake actuator and the wheel cylinder.
(b) Check that the brake is not dragging.
OK:
There is no fluid leaks or dragging.
NG -- REPAIR OR REPLACE APPLICABLE PART
OK -- Continue to next step.
2. PERFORM AIR BLEEDING
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Perform the air bleeding procedure in Bleed Brake System Service and Repair.
NEXT -- Continue to next step.
3. CHECK BRAKE BOOSTER WITH MASTER CYLINDER (ACTUATOR SIDE)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(b) Disconnect the skid control ECU connector 2 minutes after the power switch is turned off.
(c) Check both the connector case and the terminal for deformation and corrosion.
OK:
No deformation or corrosion.
NG -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (VEHICLE SIDE)
(a) Measure the voltage and resistance on the wire harness side Pinout Values and Diagnostic Parameters.
OK:
Voltage and resistance readings are all normal.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. READ VALUE USING TECHSTREAM (WHEEL CYLINDER PRESSURE SENSOR)
(a) Reconnect the skid control ECU connector.
(b) Connect a pedal effort gauge Component Tests and General Diagnostics.
(c) Connect the Techstream to the DLC3.
(d) Turn the power switch on (IG).
(e) Select the Data List on the Techstream Data List / Active Test.
ABS/VSC/TRAC
(f) Check the output value of the wheel cylinder pressure sensor at each hydraulic pressure level during the electronically controlled brake system control.
Standard Voltage:
for Front Wheel Cylinder Pressure Sensor LH
for Front Wheel Cylinder Pressure Sensor RH
NG -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
OK -- Continue to next step.
6. CHECK BRAKE DISC
(a) Turn the power switch off.
(b) Disconnect the brake pedal stroke sensor connector.
(c) Perform a road 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
* An unevenly worn disc may vibrate the caliper piston and cause fluctuations in brake line pressure, triggering a malfunction detection condition.
* 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.
* The Active Test does not prohibit electronically controlled brake system control when driving the vehicle, so disconnect the stroke sensor connector before continuing with inspection.
* Disc uneven wear can be checked by measuring the disc thickness variation Front Brake for front, or Rear Brake for rear).
NG -- REPLACE BRAKE DISC
OK -- Continue to next step.
7. RECONFIRM DTC
(a) Reconnect the brake pedal stroke sensor connector.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Perform a road test under the same malfunction conditions recreated based on the Freeze Frame Data or customer problem analysis.
(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:
HINT
If the DTC is no longer output, it can be suspected that it was output due to an improperly connected connector.
B -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting