Inspection Procedure

NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (see INITIALIZATION ).

CHECK BRAKE FLUID LEVEL IN RESERVOIR

Check that the brake fluid level is sufficient.
OK: Brake fluid level is proper.

HINT:
- If the fluid level drops, check for a fluid leak, and repair if found.
- Check that the brake fluid leakage (Connection between accumulator and actuator, or actuator and wheel cylinder)
- If no leak exists, add and adjust fluid and then check that the trouble code is not output again.
  
  Fig 1: Checking Brake Fluid Level In Reservoir
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check that there are no leaks from the connection between the accumulator pump and actuator.

HINT:

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

Bleed air from the brake actuator (see REPLACEMENT ).

Using the Techstream, check the data monitor of the accumulator pressure sensor.

Fig 2: Locating Accumulator Pump Nuts

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

ABS/VSC/TRAC

TESTER DISPLAY REFERENCE CHART

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Accumulator Sensor	Accumulator pressure sensor/min.: 0 V, max.: 5 V	Specified value: 3.2 to 4.0 V	-

Wait for 30 seconds without operating the brake pedal. Then check the accumulator pressure sensor output value's change is within the specified range.
OK: Accumulator pressure sensor output value's change is within 0.2 V.

NG: CHECK AND REPAIR BRAKE FLUID LEAKAGE AND ADD FLUID

OK: Go to Next Step

INSPECT BRAKE FLUID LEVEL WARNING SWITCH

Disconnect the A18 switch connector.

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

HINT:

A float is placed inside the reservoir. Its position can be changed by increasing/decreasing the level of brake fluid.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART

Tester Connection	Switch Condition	Specified Condition
1 (GND) - 2 (LBL)	Float up (Switch OFF)	1.84 to 2.16 kΩ
1 (GND) - 2 (LBL)	Float down (Switch ON)	Below 1 Ω

HINT:

If there is no problem after finishing the above check, adjust the brake fluid level to the MAX level.

Fig 3: Identifying Brake Fluid Level Warning Switch Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY

OK: Go to Next Step

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

Disconnect the A19 ECU connector.
Disconnect the A18 switch connector.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART

Tester Connection	Condition	Specified Condition
A19-45 (LBL) - A18-2 (LBL)	Always	Below 1 Ω
A19-45 (LBL) - Body ground	Always	10 kΩ or higher
A18-1 (GND) - Body ground	Always	Below 1 Ω

Fig 4: Identifying A19 And A18 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

CHECK SKID CONTROL ECU (SWITCH INPUT VOLTAGE)

Reconnect the A19 ECU connector.
Disconnect the A18 switch connector.
Turn the engine switch on (IG).

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

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART

Tester Connection	Switch Condition	Specified Condition
A18-2 - Body ground	Always	8 to 14 V

Fig 5: Identifying A18 Switch Connector Terminals

NG: REPLACE SKID CONTROL ECU (See REMOVAL )

OK: Go to Next Step

RECONFIRM DTC

Clear the DTCs (see DTC CHECK/CLEAR ).
Turn the engine switch on (IG).

Check if the same DTC is recorded (see DTC CHECK/CLEAR ).

HINT:

Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result

RESULT CHART

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

HINT:

If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step (see PROBLEM SYMPTOMS TABLE ).

B: END

A: REPLACE SKID CONTROL ECU (See REMOVAL )