Inspection Procedure

NOTE: When replacing the skid control ECU or brake actuator assembly, perform initialization of linear solenoid valve and calibration (See INITIALIZATION ).

HINT:

When C1241/41, C1252/52 or C1253/53 is output together with C1256/57, inspect and repair the trouble areas indicated by C1241/41, C1252/52 or C1253/53 first.
DTCs may be output if the accumulator pressure drops due to frequent braking (this is not a malfunction).

PROBLEM CHECK

Ask the customer if frequent braking is performed when the brake control warning light comes on.

CONDITION REFERENCE

Condition	Proceed To
Frequent braking is performed	A
Frequent braking is not performed	B

HINT:

This DTC is output even if the accumulator pressure drops only temporarily due to frequent braking.

B: END

A: Go to next step

INSPECT BRAKE ACTUATOR ASSEMBLY

Disconnect the brake actuator assembly connector.

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

Resistance

RESISTANCE SPECIFICATION CHART

Tester Connection	Specified Condition
32 (BM2) - 1 (GND1)	Below 10 Ω
31 (BM1) - 1 (GND1)	Below 10 Ω
32 (BM2) - 31 (BM1)	Below 1 Ω
1 (GND1) - 2 (GND2)	Below 1 Ω
32 (BM2) - 3 (MTT)	About 10 Ω
31 (BM1) - 3 (MTT)	About 10 Ω

Fig 1: Identifying Brake Actuator Assembly Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE BRAKE ACTUATOR ASSEMBLY

OK: Go to next step

READ VALUE OF TECHSTREAM (ACCUMULATOR PRESSURE SENSOR)

Connect Techstream to the DLC3.
Turn the ignition switch on.

Select the Data List mode on Techstream.

ABS/VSC/TRAC:

ABS/VSC/TRAC DATA LIST REFERENCE

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

Depress the brake pedal 4 or 5 times to operate the pump motor, and check the output value on Techstream with the motor stopped (not braking).
OK: ACC pressure sensor's output voltage does not drop.

NG: REPLACE BRAKE ACTUATOR ASSEMBLY

OK: REPLACE SKID CONTROL ECU