DTC C1251: Open in Pump Motor Circuit [08/2015 - ]: Procedure

1. Remove the hydraulic brake booster assembly (Refer to REMOVAL [08/2015 - ] ).
2. Check the tightening torque of the 2 screws which secure the wire harness connecting the master cylinder solenoid and brake booster with accumulator pump assembly (Refer to PROCEDURE - Step 5 ).

   OK

   The harness is tightened to the specified torque.

   Torque: 2.9 N*m (30 kgf*cm, 26 in.*lbf) 

Result: 

NG 

RETIGHTEN SCREWS 

Result: 

OK 

See step  2

1. Using a screwdriver, remove the 2 screws and pull out the wire harness from the master cylinder solenoid.
2. 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
   Red wire terminal - Black wire terminal	Always	Below 2 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Pump motor wire harness
   *a	Red wire
   *b	Black wire

Result: 

NG 

REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY 

(Refer to DISASSEMBLY [08/2015 - ] )

Result: 

OK 

See step  3

1. Reassemble the hydraulic brake booster assembly (Refer to REASSEMBLY [08/2015 - ] ).
2. Install the hydraulic brake booster assembly (Refer to INSTALLATION [08/2015 - ] ).
3. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] , or refer to DTC CHECK / CLEAR [08/2019 - ] ).
4. Turn the ignition switch off.
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 - ] ).
   RESULT
   
   

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

Result: 

A 

REPLACE MASTER CYLINDER SOLENOID 

(Refer to DISASSEMBLY [08/2015 - ] )

Result: 

B 

USE SIMULATION METHOD TO CHECK 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - 08/2019] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ] )