DTC C1252/52: Brake Booster Pump Motor on Time Abnormally Long; DTC C1253/53: Pump Motor Relay Malfunction: Procedure

PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY)

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

Select the Active Test on the Techstream, refer to DATA LIST / ACTIVE TEST .

ABS/VSC/TRAC

Tester Display	Test Part	Control Range	Diagnostic Note
ECB* Motor Relay	Motor relay 1	Relay ON/OFF	Operation sound of relay (clicking sound) and motor can be heard
ECB* Motor Relay2	Motor relay 2	Relay ON/OFF	Operation sound of relay (clicking sound) and motor can be heard

*: Electronically Controlled Brake System

Check the operation sound of the motor relay and motor when operating the relay using the Techstream.
OK

The operation sound of the motor relay and motor can be heard.

NG → See step 6

OK: Go to next step

INSPECT BRAKE BOOSTER PUMP

Turn the ignition switch off.

Fig 1: Identifying Brake Booster Pump Connectors Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Make sure that there is no looseness at the locking part and the connecting part of the connectors.
Disconnect the brake booster pump connectors.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A53-2 (BM1) - A53-4 (GND1)	Always	Below 10 Ω
A54-2 (BM2) - A53-4 (GND1)	Always	Below 10 Ω
A53-2 (BM1) - A54-2 (BM2)	Always	Below 1 Ω
A53-4 (GND1) - A54-1 (GND2)	Always	Below 1 Ω
A53-2 (BM1) - A53-1 (MTT)	Always	950 to 1050 Ω
A54-2 (BM2) - A53-1 (MTT)	Always	950 to 1050 Ω

TEXT IN ILLUSTRATION

*1	Component without harness connected (Brake Booster Pump)

NG → See step 13

OK: Go to next step

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE BOOSTER PUMP)

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

Fig 2: Identifying Skid Control ECU And Brake Booster Pump Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the A46 skid control ECU connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A46-29 (MTT) - A53-1 (MTT)	Always	Below 1 Ω
A46-29 (MTT) - Body ground	Always	10 kΩ or higher
A53-4 (GND1) - Body ground	Always	Below 1 Ω
A54-1 (GND2) - Body ground	Always	Below 1 Ω

TEXT IN ILLUSTRATION

*1	Front view of wire harness connector (to Skid Control ECU)
*2	Front view of wire harness connector (to Brake Booster Pump)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE SENSOR)

Reconnect the skid control ECU connector and the brake booster pump connectors.
Connect the Techstream to the DLC3.
Turn the ignition switch to ON.

Select the Data List on the Techstream, refer to DATA LIST / ACTIVE TEST .

ABS/VSC/TRAC

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Accumulator Sensor	Accumulator pressure sensor / Min.: 0.00 V, Max.: 5.00 V	Specified value: 2.6 to 3.8 V	When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

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 → See step 11

OK: Go to next step

RECONFIRM DTC

Turn the ignition switch off.
Clear the DTCs, refer to DTC CHECK / CLEAR .
Turn the ignition switch to ON.

Check if the same DTC is recorded, refer to DTC CHECK / CLEAR .

Result

Result	Proceed to
DTCs (C1252/52 and C1253/53) are not output	A
DTCs (C1252/52 and/or C1253/53) are output	B

B → See step 14

A → See step 12

INSPECT ABS NO. 1, 2 FUSE

Turn the ignition switch off.

Fig 3: Identifying ABS No. 1, 2 Fuse
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Remove the fusible link block from the engine room relay block.
Check if the fusible link is melted.
OK

The fusible link is not melted.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
ABS NO. 1 (50 A) fuse - Body ground	Always	Below 1 Ω
ABS NO. 2 (50 A) fuse - Body ground	Always	Below 1 Ω

TEXT IN ILLUSTRATION

*1	Engine Room Relay Block
*2	ABS NO. 1 Fuse
*3	ABS NO. 2 Fuse

NG → REPLACE FUSIBLE LINK BLOCK (ABS NO. 1, 2 FUSE)

OK: Go to next step

INSPECT ABS MOTOR RELAY (ABS MTR1, 2)

Install the fusible link block to the engine room No. 2 relay block.

Fig 4: Identifying Headlight Relay
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Remove the ABS MTR1 relay and the ABS MTR2 relay.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
3 - 5	Voltage is not applied between terminals 1 and 2	10 kΩ or higher
3 - 5	Voltage is applied between terminals 1 and 2	Below 1 Ω

NG → REPLACE ABS MOTOR RELAY (ABS MTR1, 2)

OK: Go to next step

INSPECT ENGINE ROOM NO. 2 RELAY BLOCK (POWER SOURCE TERMINAL)

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

Fig 5: Identifying Engine Room No. 2 Relay Block (Power Source Terminal)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard Voltage

Tester Connection	Condition	Specified Condition
ABS MTR1 relay terminal 5 - Body ground	Always	11 to 14 V
ABS MTR2 relay terminal 5 - Body ground	Always	11 to 14 V

TEXT IN ILLUSTRATION

*1	Engine Room No. 2 Relay Block
*2	ABS MTR1 Relay
*3	ABS MTR2 Relay

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

OK: Go to next step

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER PUMP - ENGINE ROOM NO. 2 RELAY BLOCK)

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

Fig 6: Identifying A53, A54 Connectors (Brake Booster Pump - Engine Room No. 2 Relay Block)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the brake booster pump connectors.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A53-2 (BM1) - ABS MTR1 relay terminal 3	Always	Below 1 Ω
A53-2 (BM1) - Body ground	Always	10 kΩ or higher
A54-2 (BM2) - ABS MTR2 relay terminal 3	Always	Below 1 Ω
A54-2 (BM2) - Body ground	Always	10 kΩ or higher

TEXT IN ILLUSTRATION

*1	Front view of wire harness connector (to Brake Booster Pump)
*2	Engine Room No. 2 Relay Block
*3	ABS MTR1 Relay
*4	ABS MTR2 Relay

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 2 RELAY BLOCK)

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

Fig 7: Identifying A45 And A46 Skid Control ECU Connectors & Engine Room No. 2 Relay Block
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the A45 and A46 skid control ECU connectors.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A46-11 (MR1) - ABS MTR1 relay terminal 1	Always	Below 1 Ω
A46-11 (MR1) - Body ground	Always	10 kΩ or higher
A46-24 (R1-) - ABS MTR1 relay terminal 2	Always	Below 1 Ω
A46-24 (R1) - Body ground	Always	10 kΩ or higher
A45-14 (R2-) - ABS MTR2 relay terminal 2	Always	Below 1 Ω
A45-14 (R2-) - Body ground	Always	10 kΩ or higher
A45-17 (MR2) - ABS MTR2 relay terminal 1	Always	Below 1 Ω
A45-17 (MR2) - Body ground	Always	10 kΩ or higher

TEXT IN ILLUSTRATION

*1	Front view of wire harness connector (to Skid Control ECU)
*2	Engine Room No. 2 Relay Block
*3	ABS MTR1 Relay
*4	ABS MTR2 Relay

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 14

PERFORM ACTIVE TEST USING TECHSTREAM (SOLENOID VALVE)

Select the Active Test on the Techstream, refer to DATA LIST / ACTIVE TEST .

HINT:

The Active Test can be performed when the following conditions are met.

Main relays 1 and 2 are on.
Shift lever is in P.
Parking brake is applied.
Vehicle speed is 0 km/h (0 mph).

ABS/VSC/TRAC

Tester Display	Test Part	Control Range	Diagnostic Note
ECB* Solenoid (SMC1)	Master cut solenoid (SMC1)	Solenoid ON/OFF	Operation sound of solenoid (clicking sound) can be heard
ECB* Solenoid (SMC2)	Master cut solenoid (SMC2)	Solenoid ON/OFF	Operation sound of solenoid (clicking sound) can be heard
ECB* Solenoid (SLRRL) Value Close	Linear solenoid (RLR) valve	Valve close ON/OFF	-
ECB* Solenoid (SLRRR) Value Close	Linear solenoid (RRR) valve	Valve close ON/OFF	-

*: Electronically Controlled Brake System

Perform the Active Test of the solenoid using the Techstream.

Fig 8: Identifying Brake Actuator Inner Diagram
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Select the Data List on the Techstream, refer to DATA LIST / ACTIVE TEST .

ABS/VSC/TRAC

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
FR W/C Sensor	FR wheel cylinder pressure sensor / Min.: 0.00 V, Max.: 5.00 V	When brake pedal is released: 0.3 to 0.7 V	Reading increases when brake pedal is depressed
FL W/C Sensor	FL wheel cylinder pressure sensor / Min.: 0.00 V, Max.: 5.00 V	When brake pedal is released: 0.3 to 0.7 V	Reading increases when brake pedal is depressed
RR W/C Sensor	RR wheel cylinder pressure sensor / Min.: 0.00 V, Max.: 5.00 V	When brake pedal is released: 0.3 to 0.7 V	Reading increases when brake pedal is depressed
RL W/C Sensor	RL wheel cylinder pressure sensor / Min.: 0.00 V, Max.: 5.00 V	When brake pedal is released: 0.3 to 0.7 V	Reading increases when brake pedal is depressed

Check that the output value of each wheel cylinder does not increase.
OK

The output value of each wheel cylinder does not increase.

HINT:

If any output value increases, there may be a brake fluid leak in the brake actuator.

NG → See step 15

OK → See step 13

CHECK FOR INTERMITTENT PROBLEMS. Refer to HOW TO PROCEED WITH TROUBLESHOOTING
REPLACE BRAKE BOOSTER PUMP. Refer to REMOVAL
REPLACE SKID CONTROL ECU. Refer to REMOVAL
REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to REMOVAL