ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1252

DESCRIPTION

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   CHECK PUMP MOTOR OPERATION

   
   

   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.

      Table 1. 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

      Tip:

      Refer to the hydraulic brake booster assembly installation procedures:

      
      

      • for LHD (Click here)

      • for RHD (Click here)

   
   
   • AClick here
   • BClick here
   • CClick here
   • DClick here
2. Click here

   CHECK CONNECTION OF PUMP MOTOR WIRE HARNESS

   
   

   1. Remove the hydraulic brake booster assembly (for LHD:Click here, for RHD:Click here).

   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 (for LHD:Click here, for RHD:Click here).

      OK
      The harness is tightened to the specified torque.

   
   
   • OKClick here
   • NGClick here
3. Click here

   CHECK RESISTANCE OF PUMP MOTOR WIRE HARNESS

   
   

   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.

      Standard Resistance
      Tester Connection Condition Specified Condition Red wire terminal - Black wire terminal Always Below 2 Ω

      Table 2. Text in Illustration

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

      Tip:
      

      • Refer to the brake booster with accumulator pump assembly installation procedures:

      • for LHD (Click here)

      • for RHD (Click here)

   
   
   • OKClick here
   • NGClick here
4. Click here

   READ VALUE USING GTS (ACCUMULATOR SENSOR)

   
   

   1. Turn the ignition switch off.

   2. Connect the GTS to the DLC3.

   3. Turn the ignition switch to ON.

   4. Turn the GTS on.

   5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      Table 3. ABS/VSC/TRC

      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.

      Table 4. 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

      Tip:
      

      • Refer to the hydraulic brake booster assembly installation procedures:

        for LHD (Click here)

        for RHD (Click here)

      • Refer to the master cylinder solenoid installation procedures:

        for LHD (Click here)

        for RHD (Click here)

   
   
   • AClick here
   • BClick here
   • CClick here
5. Click here

   RECONFIRM DTC

   
   

   1. Clear the DTCs (Click here).

   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 (Click here).

      Table 5. Result

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

      Tip:
      

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

      • Refer to the hydraulic brake booster assembly installation procedures:

        for LHD (Click here)

        for RHD (Click here)

      • Refer to the brake booster with accumulator pump assembly installation procedures:

        for LHD (Click here)

        for RHD (Click here)

   
   
   • AClick here
   • BClick here
6. Click here

   REPLACE HYDRAULIC BRAKE BOOSTER ASSEMBLY

7. Click here

   RETIGHTEN SCREWS

8. Click here

   REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY

9. Click here

   REPLACE MASTER CYLINDER SOLENOID