DTC C1252: Brake Booster Pump Motor on Time Abnormally Long [08/2015 - ]: Procedure

1. Turn the ignition switch off.
2. Depress the brake pedal more than 40 times.
3. Turn the ignition switch to ON.
4. Check how the pump motor operates.
   RESULT
   
   

   Result	Proceed to
   Pump motor does not operate	A
   Pump motor operates continuously and does not stop	B
   Pump motor operates intermittently	C
   Pump motor operates, and then stops	D

Result: 

B 

REPLACE HYDRAULIC BRAKE BOOSTER ASSEMBLY 

(Refer to REMOVAL [08/2015 - ] )

Result: 

C 

See step  4

Result: 

D 

See step  5

Result: 

A 

See step  2

See step  1

Result: 

NG 

RETIGHTEN SCREWS 

Result: 

OK 

See step  3

See step  2

Result: 

NG 

REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY 

(Refer to DISASSEMBLY [08/2015 - ] )

Result: 

OK 

See step  4

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Accumulator Sensor	Accumulator pressure sensor reading/ Min.: 0.00 V, Max.: 5.00 V	3.58 to 5 V	If the value is constant regardless of the pump operation, an accumulator pressure sensor malfunction is suspected.

6. Check the accumulator output value.
   RESULT
   
   

   Result	Proceed to
   Output value is within "Normal Condition" range	A
   Output value is out of "Normal Condition" range	B
   Output value is constant regardless of pump operation	C

Result: 

B 

REPLACE MASTER CYLINDER SOLENOID 

(Refer to DISASSEMBLY [08/2015 - ] )

Result: 

C 

REPLACE HYDRAULIC BRAKE BOOSTER ASSEMBLY 

(Refer to REMOVAL [08/2015 - ] )

Result: 

A 

See step  5

1. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] , or refer to DTC CHECK / CLEAR [08/2019 - ] ).
2. Turn the ignition switch off.
3. Turn the ignition switch to ON.
4. Wait for more than 5 minutes.
5. Check if the same DTC is output (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] , or refer to DTC CHECK / CLEAR [08/2019 - ] ).

   HINT: 

   Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

   RESULT
   
   

   Result	Proceed to
   DTC is output	A
   DTC is not output	B

Result: 

A 

REPLACE HYDRAULIC BRAKE BOOSTER ASSEMBLY 

(Refer to REMOVAL [08/2015 - ] )

Result: 

B 

REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY 

(Refer to DISASSEMBLY [08/2015 - ] )