DTC C1202/68: Master Reservoir Level Malfunction [03/2017 - 09/2018]: Procedure

1. Check that the brake fluid level is sufficient.

   HINT: 

   • If the fluid level is low, check for fluid leaks, and repair as necessary.
   • Check for brake fluid leaks (connection between the brake booster with accumulator pump assembly, brake master cylinder reservoir assembly and the brake actuator assembly, and between the brake actuator assembly and wheel cylinders).
   • If no leaks exist, add and adjust fluid and then check that the trouble code is not output again.

   OK

   Brake fluid level is sufficient.

2. Check that there are no leaks from the connections between the brake booster with accumulator pump assembly and brake actuator assembly.

   HINT: 

   As a visual check is very difficult, perform the check with the following procedure.

   1. Bleed air from the brake actuator assembly.

      Refer to BLEEDING [03/2017 - ]

   2. Connect the Techstream to the DLC3.
   3. Turn the engine switch on (IG).
   4. Select the Data List on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [03/2017 - 05/2023]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
      Accumulator Sensor	Accumulator pressure sensor	Min.: 0.00 V, Max.: 5.00 V	Specified value: 2.60 to 3.80 V	When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

   5. Depress the brake pedal 4 or 5 times to operate the pump motor.
   6. Wait for 30 seconds without depressing the brake pedal.
   7. Check that the accumulator pressure sensor output value change is within the specified range.

      OK

      Accumulator pressure sensor output value change is less than 0.20 V.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CHECK AND REPAIR BRAKE FLUID LEAKS OR ADD FLUID 

Result: 

OK 

See step  2

1. Remove the brake master cylinder reservoir filler cap and strainer.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component without harness connected (Brake Fluid Level Warning Switch (Brake Master Cylinder Reservoir Assembly))

2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the A17 brake fluid level warning switch (brake master cylinder reservoir assembly) connector.
4. 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	Condition	Specified Condition
   2 (LBL) - 1 (GND)	Brake fluid level warning switch (Brake master cylinder reservoir assembly) off (float up)	1.84 to 2.16 kΩ
   2 (LBL) - 1 (GND)	Brake fluid level warning switch (Brake master cylinder reservoir assembly) on (float down)	Below 1 Ω

   HINT: 

   If there are no problems after completing the preceding inspection, adjust the brake fluid to the MAX level with the engine switch on (IG).

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023] 

Result: 

OK 

See step  3

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.
2. Disconnect the A9 skid control ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A9-6 (LBL) - A17-2 (LBL)	Always	Below 1 Ω
   A9-6 (LBL) or A17-2 (LBL) - Body ground	Always	10 kΩ or higher
   A17-1 (GND) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Reconnect the A9 skid control ECU assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Skid Control ECU Assembly)

2. Reconnect the A17 brake fluid level warning switch (brake master cylinder reservoir assembly) connector.
3. Turn the engine switch on (IG).
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A9-6 (LBL) - Body ground	Brake fluid level warning switch (Brake master cylinder reservoir assembly) off → on	4 to 8 V → Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023] 

Result: 

OK 

See step  5

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [03/2017 - 09/2018]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

2. Turn the engine switch off.
3. Turn the engine switch on (IG).
4. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [03/2017 - 09/2018]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result

   Result	Proceed to
   DTC C1202/68 is not output.	A
   DTC C1202/68 is output.	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2017 - 04/2020] 

Result: 

B 

REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023]