DTC C1391: Abnormal Leak in Accumulator [04/2018 -]: Procedure
- READ VALUE USING TECHSTREAM (SERVO PRESSURE)
- Select the Active Test on the Techstream.
Refer to DATA LIST / ACTIVE TEST [04/2018 -]
Chassis > ABS/VSC/TRAC > Active Test
Tester Display Measurement Item Control Range Diagnostic Note ECB Solenoid (SLR) Linear solenoid reduction valve (SLR) Solenoid ON/OFF ECB: Electronically Controlled Brake System Chassis > ABS/VSC/TRAC > Data List
Tester Display Measurement Item Range Normal Condition Diagnostic Note Servo Pressure Pressure value of servo Min.: 0.00 MPa, Max.: 24.48 MPa Brake pedal released: 0.00 to 2.10 MPa Brake pedal is being depressed: Changes in proportion to the depression force of the brake pedal Chassis > ABS/VSC/TRAC > Active Test
Active Test Display ECB Solenoid (SLR) Data List Display Servo Pressure - Perform the Active Test and operate the linear solenoid (SLR) in the brake actuator (brake booster with master cylinder assembly).
- Check that the servo pressure output value does not increase when performing the Active Test.
OK
The servo pressure output value does not increase when performing the Active Test.
HINT:
If the servo pressure output value increases, an internal brake fluid leak in the brake actuator (brake booster with master cylinder assembly) is suspected.
Result
Result Proceed to The servo pressure output value increases. A The servo pressure output value does not increase. B
Result:
A
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to REMOVAL [04/2018 - 08/2021] , or refer to REMOVAL [08/2021 -]
Result:
B
See step 2
- Select the Active Test on the Techstream.
- CHECK OPERATING TIME OF PUMP MOTOR
- Turn the power switch on (READY).
- Select the Data List on the Techstream.
Refer to DATA LIST / ACTIVE TEST [04/2018 -]
Chassis > ABS/VSC/TRAC > Data List
Tester Display Measurement Item Range Normal Condition Diagnostic Note MT Voltage Value MT voltage value Min.: 0.00 V, Max.: 20.00 V Pump motor off: 0.00 V
Pump motor on: 12.00 V- Chassis > ABS/VSC/TRAC > Data List
Tester Display MT Voltage Value - With the power switch on (READY), check the operation of the pump motor.
OK
The pump motor operates once or more within 20 seconds or operates for 10 seconds or more each time.
Result
Proceed to OK NG
Result:
NG
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to REMOVAL [04/2018 - 08/2021] , or refer to REMOVAL [08/2021 -]
Result:
OK
See step 3
- CHECK FOR FLUID LEAK
- Check for brake fluid leaks in the line from the brake booster pump assembly to the brake booster with master cylinder assembly.
Refer to PROCEDURE - Step 2
OK
There are no brake fluid leaks.
Result
Proceed to OK NG
Result:
OK
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER PUMP ASSEMBLY
for the brake booster with master cylinder assembly: Refer to REMOVAL [04/2018 - 08/2021] , or refer to REMOVAL [08/2021 -]
for the brake booster pump assembly: Refer to REMOVAL [04/2018 - 08/2021] , or refer to REMOVAL [08/2021 -]
Result:
NG
REPAIR MALFUNCTIONING PART
- Check for brake fluid leaks in the line from the brake booster pump assembly to the brake booster with master cylinder assembly.