DESCRIPTION
The DTC is stored if a brake fluid, internal or other leak is detected due to improper sealing in the brake actuator or brake accumulator pump. Internal leakage is suspected if the pump motor operates frequently without braking.
DTC Code | Information Code | DTC Detection Condition | Trouble Area |
---|---|---|---|
C1391/69 | 591 | When either of the following is detected:
|
|
CAUTION / NOTICE / HINT
Note
When replacing the skid control ECU or brake actuator, perform initialization of linear solenoid valve and calibration Click here.
PROCEDURE
CHECK BRAKE FLUID LEAKAGE
*1 | Brake Booster Pump |
*2 | Brake Actuator |
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.
Check that the brake is not dragging.
OK |
---|
There is no fluid leakage or dragging. |
NG |
REPAIR OR REPLACE APPLICABLE PART |
OK |
CHECK DTC
Clear the DTC Click here.
Turn the engine switch off.
Turn the engine switch on (IG).
Check if the same DTC C1391 is recorded.
Result | Proceed to | |
---|---|---|
DTC C1391 is output | A | |
DTC C1391 is not output | for LHD | B |
for RHD | C |
B |
REPLACE BRAKE ACCUMULATOR PUMP Click here |
C |
REPLACE BRAKE ACCUMULATOR PUMP Click here |
A |
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SMC1, SMC2, SLRRR, AND SLRRL)
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the intelligent tester main switch on.
Select the ACTIVE TEST mode on the intelligent tester.
Tech Tips
The ACTIVE TEST can be performed when the following conditions are met.
Main relay 1 and 2 are on.
Shift lever is P position.
Parking brake is on.
Vehicle speed is 0 km/h (0 mph).
Tester Display | Test Part | Control Range | Diagnostic Note |
---|---|---|---|
Electronically Controlled Brake System Solenoid (SCC) | Turns electronically controlled brake system solenoid (SMC2) | ON / OFF | Operation sound of solenoid (clicking sound) can be heard |
Electronically Controlled Brake System Solenoid (SMC) | Turns electronically controlled brake system solenoid (SMC1) | ON / OFF | Operation sound of solenoid (clicking sound) can be heard |
Electronically Controlled Brake System Solenoid (SLRRR) Valve Close | Turns SLRRR solenoid | ON / OFF | Operation sound of solenoid (clicking sound) can be heard |
Electronically Controlled Brake System Solenoid (SLRRL) Valve Close | Turns SLRRL solenoid | ON / OFF | Operation sound of solenoid (clicking sound) can be heard |
Using the intelligent tester, turn SMC1, SMC2, SLRRR, or SLRRL ON.
Check that each wheel cylinder's output value does not increase.
OK |
---|
Each wheel cylinder's output value does not increase. |
Tech Tips
If any of wheel cylinder's output value increases, there may be a brake fluid leak in the brake actuator.
Result | Proceed to | |
---|---|---|
Any of wheel cylinder's output value increases. | for LHD | A and C* |
for RHD | B and D* |
|
Each wheel cylinder's output value does not increase. | for LHD | C |
for RHD | D |
Tech Tips
*: Replace the brake actuator and brake accumulator pump.
A |
REPLACE BRAKE ACTUATOR Click here |
B |
REPLACE BRAKE ACTUATOR Click here |
C |
REPLACE BRAKE ACCUMULATOR PUMP Click here |
D |
REPLACE BRAKE ACCUMULATOR PUMP Click here |