DTC    C1202/68    Master Reservoir Level Malfunction

for Preparation Click here


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.

DTC Code
INF Code
DTC Detection Condition
Trouble Area
C1202/68
371
An open is detected in the switch signal circuit for 2 seconds or more.
  1. Brake master cylinder reservoir (Brake fluid level warning switch) internal open circuit
  2. Open in wire harness
  3. Brake booster with master cylinder (Skid control ECU)
↑
-
The reservoir level remains low.
  1. Low brake fluid level
  2. Brake fluid leaks
  3. Brake master cylinder reservoir (Brake fluid level warning switch) internal short circuit
  4. Short in wire harness
  5. Brake disc rotor excessive wear
  6. Brake booster with master cylinder (Skid control ECU)

WIRING DIAGRAM


C209586E04


INSPECTION PROCEDURE

NOTICE:
When replacing the brake booster with master cylinder (skid control ECU), perform initialization and calibration of the linear solenoid valve (Click here).

HINT:
When releasing the parking brake, chock the wheels for safety.

1.CHECK BRAKE FLUID LEVEL

  1. 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 intelligent tester (Click here).

    2. Check that the trouble code is not output again (Click here).

  1. 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 (Click here).

    2. Connect the intelligent tester to the DLC3.

    3. Turn the power switch on (IG).

    4. Select the Data List on the intelligent tester (Click here).

      ABS/VSC/TRC 
      Tester Display
      		Measurement Item/Range
      		Normal Condition
      		Diagnostic Note
      Accumulator Sensor
      		Accumulator pressure sensor / Min.: 0 V, Max.: 5 V
      		Specified value: 2.9 to 4.2 V
      		When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

    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


2.INSPECT BRAKE FLUID LEVEL WARNING SWITCH


    C213271E02

  1. Turn the power switch off.

  1. Remove the reservoir filler cap and strainer.

  1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

  1. Disconnect the brake fluid level warning switch connector.

  1. 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:
    Tester Connection
    		Switch Condition
    		Specified Condition
    1 (+) - 2 (E)
    		Brake fluid level warning switch OFF (Float up)
    		1.84 to 2.16 kΩ
    1 (+) - 2 (E)
    		Brake fluid level warning switch ON (Float down)
    		Below 1 Ω

    Text in Illustration 
    *a
    		Component without harness connected
    (Brake Fluid Level Warning Switch)

    Result:

    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C



B
REPLACE BRAKE MASTER CYLINDER RESERVOIR (BRAKE FLUID LEVEL WARNING SWITCH) (Click here)

C
REPLACE BRAKE MASTER CYLINDER RESERVOIR (BRAKE FLUID LEVEL WARNING SWITCH) (Click here)
A


3.CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE FLUID LEVEL WARNING SWITCH)

  1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

  1. Disconnect the skid control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A61-36 (LBL) - A31-1 (+)
    		Always
    		Below 1 Ω
    A61-36 (LBL) - Body ground
    		Always
    		10 kΩ or higher
    A31-2 (E) - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.INSPECT SKID CONTROL ECU (SWITCH INPUT)


    C156573E04

  1. Reconnect the skid control ECU connector.

  1. Turn the power switch on (IG).

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A31-1 (+) - Body ground
    		Power switch on (IG)
    		4 to 7 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Brake Fluid Level Warning Switch)

    Result:

    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A


5.CHECK BRAKE DISC

  1. Turn the power switch off.

  1. Reconnect the brake fluid level warning switch connector.

  1. Disconnect the brake pedal stroke sensor connector.

  1. 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:
    1. An unevenly worn disc may vibrate the caliper piston and cause fluctuations in brake line pressure, triggering a malfunction detection condition.
    2. The brake pedal does not kick back due to wheel cylinder piston vibration during electronically controlled brake system control.
    3. If the brake pedal stroke sensor connector is disconnected, the fail-safe function will prohibit electronically controlled brake system control.
    4. 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.
    5. Disc uneven wear can be checked by measuring the disc thickness variation (Click here for front, or Click here for rear).



NG
REPLACE BRAKE DISC
OK


6.RECONFIRM DTC

  1. Reconnect the brake pedal stroke sensor connector.

  1. Clear the DTCs (Click here).

  1. Turn the power switch on (READY).

  1. Perform a road test.

  1. Check if the same DTC is recorded (Click here).

    Result:

    Result
    		Proceed to
    DTC (C1202/68) is not output
    		A
    DTC (C1202/68) is output (for LHD)
    		B
    DTC (C1202/68) is output (for RHD)
    		C

    HINT:
    If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (Click here).



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A

CHECK FOR INTERMITTENT PROBLEMS (Click here)