C1202
BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1202/68: Master Reservoir Level Malfunction
C1202/68 - Master Reservoir Level Malfunction
DESCRIPTION
When a fluid level drop in the master cylinder reservoir is detected, the signal is input to the skid control ECU.
If the DTC for the fluid level drop is memorized, the warning will be canceled and the DTC will not be stored when the fluid level returns to normal.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the brake booster with master cylinder (skid control ECU), perform initialization and calibration of the linear solenoid valve Initialization.
HINT
When releasing the parking brake, chock the wheels for safety.
PROCEDURE
1. CHECK BRAKE FLUID LEVEL
(a) Check that the brake fluid level is sufficient.
OK:
Brake fluid level is sufficient.
HINT
If the fluid level is low, check for fluid leaks, and repair as necessary.
(1) Check for brake fluid leaks (Connection between the brake booster pump, brake master cylinder reservoir and brake booster with master cylinder, and the brake booster with master cylinder and wheel cylinders).
HINT
If no leaks exist, add and adjust fluid using the Techstream Testing and Inspection.
(2) Check that the trouble code is not output again Reading and Clearing Diagnostic Trouble Codes.
(b) Check that there are no leaks from the connections between the brake booster pump and brake booster with master cylinder.
HINT
As a visual check is very difficult, perform the check with the following procedure.
(1) Bleed the air from the brake systems Service and Repair.
(2) Connect the Techstream to the DLC3.
(3) Turn the power switch on (IG).
(4) Select the Data List on the Techstream Data List / Active Test.
ABS/VSC/TRAC
(5) Wait for 30 seconds without depressing the brake pedal.
(6) Check that the accumulator pressure sensor output values change is within the specified range.
OK:
Accumulator pressure sensor output values change is within 0.55 V.
NG -- CHECK AND REPAIR BRAKE FLUID LEAKS OR ADD FLUID
OK -- Continue to next step.
2. INSPECT BRAKE FLUID LEVEL WARNING SWITCH
(a) Turn the power switch off.
(b) Remove the reservoir filler cap.
(c) Make sure that there is no looseness at the locking part and the connecting part of the connector.
(d) Disconnect the brake fluid level warning switch connector.
(e) Measure the resistance according to the value(s) in the table below.
HINT
A float is located inside the reservoir. Its position changes according to the level of brake fluid.
Standard Resistance:
Text in Illustration
NG -- REPLACE BRAKE MASTER CYLINDER RESERVOIR (BRAKE FLUID LEVEL WARNING SWITCH) Removal
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE FLUID LEVEL WARNING SWITCH)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.
(b) Disconnect the skid control ECU connector.
(c) 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. INSPECT SKID CONTROL ECU (SWITCH INPUT)
(a) Reconnect the skid control ECU connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
NG -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
OK -- Continue to next step.
5. CHECK BRAKE DISC
(a) Turn the power switch off.
(b) Reconnect the brake fluid level warning switch connector.
(c) Disconnect the brake pedal stroke sensor connector.
(d) 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.
6. RECONFIRM DTC
(a) Reconnect the brake pedal stroke sensor connector.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the power switch on (READY).
(d) Perform a road test.
(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:
HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.
B -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting