DTC C1252/52: Brake Booster Pump Motor on Time Abnormally Long; DTC C1253/53: Pump Motor Relay Malfunction [08/2013 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the Active Test on the Techstream. Refer to DATA LIST / ACTIVE TEST [08/2013 - ] .
   ABS/VSC/TRAC
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   ECB* Motor Relay	ABS motor relay	Relay ON/OFF	-

   *: Electronically Controlled Brake System

4. Select the Data List on the Techstream. Refer to DATA LIST / ACTIVE TEST [08/2013 - ] .
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   ECB* Motor Relay	ABS motor relay / ON or OFF	ON: Relay on OFF: Relay off	-

   *: Electronically Controlled Brake System

5. Check the operating condition of the ABS motor relay when operating it using the Techstream.

   Result

   Result	Proceed to
   ABS motor relay in the Data List turns ON/OFF using the Active Test.	A
   ABS motor relay in the Data List does not change using the Active Test.	B

B → See step   6 

A: Go to next step 

1. Turn the power switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
3. Disconnect the A38 and A39 brake booster pump assembly connectors.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A38-2 (BM1) - A38-4 (GND1)	Always	Below 10 Ω
   A39-2 (BM2) - A39-1 (GND2)	Always	Below 10 Ω
   A38-2 (BM1) - A39-2 (BM2)	Always	Below 1 Ω
   A38-4 (GND1) - A39-1 (GND2)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Brake Booster Pump Assembly)

NG → See step   11 

OK: Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A38-4 (GND1) - Body ground	Always	Below 1 Ω
   A39-1 (GND2) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Brake Booster Pump Assembly)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

OK: Go to next step 

1. Reconnect the A38 and A39 brake booster pump assembly connectors.
2. Connect the Techstream to the DLC3.
3. Turn the power switch on (IG).
4. Select the Data List on the Techstream. Refer to DATA LIST / ACTIVE TEST [08/2013 - ] .
   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: 2.90 to 4.20 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 value change is within the specified range.

   OK

   Accumulator pressure sensor output value change is less than 0.55 V.

NG → See step   8 

OK: Go to next step 

1. Turn the power switch off.
2. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
3. Turn the power switch on (IG).
4. Check if the same DTC is output. Refer to DTC CHECK / CLEAR [08/2013 - ] .

   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   10 

A → See step   9 

1. Turn the power switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A24-1 (MRI1) - Body ground	Always	11 to 14 V
   A24-2 (MRI2) - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MRI CIRCUIT) 

OK: Go to next step 

1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
2. Disconnect the A38 and A39 brake booster pump assembly connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A24-29 (MRO1) - A38-2 (BM1)	Always	Below 1 Ω
   A24-29 (MRO1) - Body ground	Always	10 kΩ or higher
   A24-30 (MRO2) - A39-2 (BM2)	Always	Below 1 Ω
   A24-30 (MRO2) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   10 

1. Select the Active Test on the Techstream. Refer to DATA LIST / ACTIVE TEST [08/2013 - ] .

   HINT: 

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

   • ABS main relay is 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 (SMC/SRC/SCC)	Switching solenoid valve (SMC/SRC/SCC)	Solenoid ON/OFF	Operation sound of solenoid (clicking sound) can be heard

   *: Electronically Controlled Brake System

2. Perform the Active Test of the solenoid using the Techstream.
3. Select the Data List on the Techstream. Refer to DATA LIST / ACTIVE TEST [08/2013 - ] .
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Wheel Cylinder Pressure Sensor	Wheel cylinder pressure sensor / Min.: 0.00 V, Max.: 5.00 V	When brake pedal released: 0.10 to 0.90 V	Reading increases when brake pedal is depressed

4. Check that the output value of the wheel cylinder pressure sensor does not increase.

   OK

   The output value of the wheel cylinder pressure sensor does not increase.

   HINT: 

   If the output value increases, there may be brake fluid leaks in the brake actuator.

NG → See step   10 

OK → See step   11