ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1341, C1342, C1343, C1344

DTC Code	DTC Name
C1341	Hydraulic System Malfunction (FR)
C1342	Hydraulic System Malfunction (FL)
C1343	Hydraulic System Malfunction (RR)
C1344	Hydraulic System Malfunction (RL)

DESCRIPTION

The skid control ECU assembly controls braking force according to the hybrid control system regenerative braking force and provides 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.
Rotors are replaced.

Tech Tips

When replacing the brake pads, retracting the brake caliper pistons and installing new brake pads will greatly increase the clearance between the brake pads and brake discs. This will result in a significant possibility of this DTC being stored the next time the brake pedal is depressed. As this is not a malfunction, clear the DTC if it is stored for this reason.

DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	Note
C1341	Hydraulic System Malfunction (FR)	551 552 553 554 555	INF Code: 551 Decrease in FR wheel hydraulic pressure control performance. (Pressure increase malfunction) INF Code: 552 Decrease in FR wheel hydraulic pressure control performance. (Pressure decrease malfunction) INF Code: 553 Malfunctions such as leaks occur in the FR wheel pressure increase control valve. INF Code: 554, 555 Malfunctions such as leaks occur in the FR wheel pressure decrease control valve.	INF Code: 551, 552 Brake fluid leaks Brake actuator assembly INF Code: 553, 554, 555 Brake fluid leaks Brake disc rotor excessive wear Brake actuator assembly	Electronically controlled brake system DTC
C1342	Hydraulic System Malfunction (FL)	561 562 563 564 565	INF Code: 561 Decrease in FL wheel hydraulic pressure control performance. (Pressure increase malfunction) INF Code: 562 Decrease in FL wheel hydraulic pressure control performance. (Pressure decrease malfunction) INF Code: 563 Malfunctions such as leaks occur in the FL wheel pressure increase control valve. INF Code: 564, 565 Malfunctions such as leaks occur in the FL wheel pressure decrease control valve.	INF Code: 561, 562 Brake fluid leaks Brake actuator assembly INF Code: 563, 564, 565 Brake fluid leaks Brake disc rotor excessive wear Brake actuator assembly	Electronically controlled brake system DTC
C1343	Hydraulic System Malfunction (RR)	571 572 573 574 575	INF Code: 571 Decrease in RR wheel hydraulic pressure control performance. (Pressure increase malfunction) INF Code: 572 Decrease in RR wheel hydraulic pressure control performance. (Pressure decrease malfunction) INF Code: 573 Malfunctions such as leaks occur in the RR wheel pressure increase control valve. INF Code: 574, 575 Malfunctions such as leaks occur in the RR wheel pressure decrease control valve.	INF Code: 571, 572 Brake fluid leaks Brake actuator assembly INF Code: 573, 574, 575 Brake fluid leaks Brake disc rotor excessive wear Brake actuator assembly	Electronically controlled brake system DTC
C1344	Hydraulic System Malfunction (RL)	581 582 583 584 585	INF Code: 581 Decrease in RL wheel hydraulic pressure control performance. (Pressure increase malfunction) INF Code: 582 Decrease in RL wheel hydraulic pressure control performance. (Pressure decrease malfunction) INF Code: 583 There is a malfunction or leak in the RL wheel pressure increase control valve. INF Code: 584/585 There is a malfunction or leak in the RL wheel pressure decrease control valve.	INF Code: 581, 582 Brake fluid leaks Brake actuator assembly INF Code: 583, 584, 585 Brake fluid leaks Brake disc rotor excessive wear Brake actuator assembly	Electronically controlled brake system DTC

WIRING DIAGRAM

Refer to DTCs C1246 and C1364.

Click here

CAUTION / NOTICE / HINT

Note

When replacing the brake actuator assembly, perform initialization and calibration of the linear solenoid valve.

Click here

Tech Tips

When C1364 is output together with C1341, C1342, C1343 and/or C1344, inspect and repair trouble areas indicated by C1364 first.

Click here

PROCEDURE

CHECK FOR FLUID LEAK

Check that there are no fluid leaks in the brake lines between the brake actuator assembly and the wheel cylinders.

Check that the brakes are not dragging.

OK
There are no fluid leaks or dragging.

Result

Proceed to
OK
NG

REPAIR OR REPLACE APPLICABLE PART

PERFORM AIR BLEEDING

Bleed the air from the front and rear brake systems.

Click here

Result

Proceed to
NEXT

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY AND BRAKE ACTUATOR ASSEMBLY - BODY GROUND)

Make sure that there is no looseness at the locking part and the connecting part of the connectors.
Disconnect the A22 and A23 skid control ECU assembly connectors.
Disconnect the A16 brake actuator assembly connector.

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

Standard Resistance

for LHD
Tester connection	Condition	Specified condition
A22-28 (E) or A16-45 (E) - Body ground	Always	10 kΩ or higher
A22-27 (VCM) or A16-35 (VCM) - Body ground	Always	10 kΩ or higher
A22-42 (PRL) or A16-36 (PRL) - Body ground	Always	10 kΩ or higher
A22-26 (PAC1) or A16-46 (PAC1) - Body ground	Always	10 kΩ or higher
A22-14 (PMC1) or A16-38 (PMC1) - Body ground	Always	10 kΩ or higher
A22-9 (PCK1) or A16-37 (PCK1) - Body ground	Always	10 kΩ or higher
A22-44 (PFR) or A16-34 (PFR) - Body ground	Always	10 kΩ or higher
A23-44 (E2) or A16-44 (E2) - Body ground	Always	10 kΩ or higher
A23-28 (VCM2) or A16-40 (VCM2) - Body ground	Always	10 kΩ or higher
A23-45 (PFL) or A16-39 (PFL) - Body ground	Always	10 kΩ or higher
A23-43 (PRR) or A16-41 (PRR) - Body ground	Always	10 kΩ or higher
A23-14 (PMC2) or A16-43 (PMC2) - Body ground	Always	10 kΩ or higher
A23-7 (PCK2) or A16-42 (PCK2) - Body ground	Always	10 kΩ or higher

for RHD
Tester connection	Condition	Specified condition
A22-28 (E) or A16-14 (E) - Body ground	Always	10 kΩ or higher
A22-27 (VCM) or A16-10 (VCM) - Body ground	Always	10 kΩ or higher
A22-42 (PRL) or A16-11 (PRL) - Body ground	Always	10 kΩ or higher
A22-26 (PAC1) or A16-15 (PAC1) - Body ground	Always	10 kΩ or higher
A22-14 (PMC1) or A16-13 (PMC1) - Body ground	Always	10 kΩ or higher
A22-9 (PCK1) or A16-12 (PCK1) - Body ground	Always	10 kΩ or higher
A22-44 (PFR) or A16-9 (PFR) - Body ground	Always	10 kΩ or higher
A23-44 (E2) or A16-16 (E2) - Body ground	Always	10 kΩ or higher
A23-28 (VCM2) or A16-5 (VCM2) - Body ground	Always	10 kΩ or higher
A23-45 (PFL) or A16-4 (PFL) - Body ground	Always	10 kΩ or higher
A23-43 (PRR) or A16-6 (PRR) - Body ground	Always	10 kΩ or higher
A23-14 (PMC2) or A16-8 (PMC2) - Body ground	Always	10 kΩ or higher
A23-7 (PCK2) or A16-7 (PCK2) - Body ground	Always	10 kΩ or higher

Result

Result
OK
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

READ VALUE USING GTS (WHEEL CYLINDER PRESSURE SENSOR)

Reconnect the A22 and A23 skid control ECU assembly connectors.
Reconnect the A16 brake actuator assembly connector.
Connect an LSPV gauge set.
Connect the GTS to the DLC3.
Turn the power switch on (IG).

Select the Data List on the GTS.

Click here

Chassis > ABS/VSC/TRC > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
FR W/C Sensor	Front wheel cylinder pressure sensor RH	Min.: 0.00 V, Max.: 5.00 V	Brake pedal released: 0.30 to 0.70 V	Reading increases when brake pedal is depressed
FL W/C Sensor	Front wheel cylinder pressure sensor LH	Min.: 0.00 V, Max.: 5.00 V	Brake pedal released: 0.30 to 0.70 V	Reading increases when brake pedal is depressed
RR W/C Sensor	Rear wheel cylinder pressure sensor RH	Min.: 0.00 V, Max.: 5.00 V	Brake pedal released: 0.30 to 0.70 V	Reading increases when brake pedal is depressed
RL W/C Sensor	Rear wheel cylinder pressure sensor LH	Min.: 0.00 V, Max.: 5.00 V	Brake pedal released: 0.30 to 0.70 V	Reading increases when brake pedal is depressed

Chassis > ABS/VSC/TRC > Data List

Tester Display
FR W/C Sensor
FL W/C Sensor
RR W/C Sensor
RL W/C Sensor

Check the output values of the wheel cylinder pressure sensor at each hydraulic pressure level during the electronically controlled brake system control.

Standard Voltage

for Front Wheel Cylinder (for Type A Rear Brake with Sports Body Type)
Hydraulic Pressure MPa (kgf/cm², psi)	FR W/C Sensor (Tester Display)	FL W/C Sensor (Tester Display)
3.39 (34.6, 492)	0.99 to 1.39 V	0.99 to 1.39 V
4.70 (47.9, 682)	1.26 to 1.66 V	1.26 to 1.66 V

for Front Wheel Cylinder (for Type A Rear Brake with Standard Body Type)
Hydraulic Pressure MPa (kgf/cm², psi)	FR W/C Sensor (Tester Display)	FL W/C Sensor (Tester Display)
3.81 (38.9, 553)	1.08 to 1.48 V	1.08 to 1.48 V
4.70 (47.9, 682)	1.26 to 1.66 V	1.26 to 1.66 V

for Front Wheel Cylinder (for Type B Rear Brake)
Hydraulic Pressure MPa (kgf/cm², psi)	FR W/C Sensor (Tester Display)	FL W/C Sensor (Tester Display)
2.43 (24.8, 352)	0.80 to 1.20 V	0.80 to 1.20 V
4.58 (46.7, 664)	1.24 to 1.64 V	1.24 to 1.64 V

for Rear Wheel Cylinder (for Type A Rear Brake with Sports Body Type)
Hydraulic Pressure MPa (kgf/cm², psi)	RR W/C Sensor (Tester Display)	RL W/C Sensor (Tester Display)
3.39 (34.6, 492)	0.99 to 1.39 V	0.99 to 1.39 V
4.70 (47.9, 682)	1.26 to 1.66 V	1.26 to 1.66 V

for Rear Wheel Cylinder (for Type A Rear Brake with Standard Body Type)
Hydraulic Pressure MPa (kgf/cm², psi)	RR W/C Sensor (Tester Display)	RL W/C Sensor (Tester Display)
3.81 (38.9, 553)	1.08 to 1.48 V	1.08 to 1.48 V
4.70 (47.9, 682)	1.26 to 1.66 V	1.26 to 1.66 V

for Rear Wheel Cylinder (for Type B Rear Brake)
Hydraulic Pressure MPa (kgf/cm², psi)	RR W/C Sensor (Tester Display)	RL W/C Sensor (Tester Display)
2.43 (24.8, 352)	0.80 to 1.20 V	0.80 to 1.20 V
4.58 (46.7, 664)	1.24 to 1.64 V	1.24 to 1.64 V

Result

Proceed to
OK
NG

REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

CHECK BRAKE DISC

Turn the power switch off.
Disconnect the A53 brake pedal stroke sensor assembly connector.

Perform a road test according to Freeze Frame Data or customer problem analysis. While driving, check for abnormal brake pedal vibration caused by brake discs that are worn or have excess runout.

OK
Brake pedal does not vibrate during braking.

Tech Tips

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 caliper piston vibration during electronically controlled brake system control.
If the brake pedal stroke sensor assembly 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 the vehicle is being driven, so disconnect the brake pedal stroke sensor assembly connector before continuing with inspection.
Uneven disc wear can be checked by measuring the disc thickness variation.

for Front Brake: Click here

for Rear Brake: Click here

Result

Proceed to
OK
NG

REPLACE BRAKE DISC

RECONFIRM DTC

Reconnect the A50 brake pedal stroke sensor assembly connector.
Clear the DTCs.

Click here

Chassis > ABS/VSC/TRC > Clear DTCs
Perform a road test under the same malfunction conditions recreated based on the Freeze Frame Data or customer problem analysis.

Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRC > Trouble Codes

Result

Result	Proceed to
DTCs C1341, C1342, C1343 and C1344 are not output.	A
DTCs C1341, C1342, C1343 and/or C1344 are output.	B

USE SIMULATION METHOD TO CHECK Click here

REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here