Inspection Procedure

INSPECT BRAKE BOOSTER ACCUMULATOR ASSY
1. Turn the ignition switch OFF, and depress the brake pedal 40 times or more.
  HINT:
  
  When a pressure in power supply system is released, reaction force becomes lightly.
2. Install the LSPV gauge (SST) to rear brake caliper and bleed air.
3. Depress the brake pedal with force of more than 343 N (35 kgf, 77 lbf) and turn the ignition switch ON, then check the rear brake caliper pressure when an increase of pressure changes from acutely to mildly.
  OK:
  
  5,099 - 8,924 kPa (52 - 91 kgf/cm ² , 740 - 1,294 psi) at 20°C (68°F)
  
  HINT:
  
  If the value is not within the standard, cool the engine room and check it again.
NG : REPLACE BRAKE BOOSTER ACCUMULATOR ASSY

OK : GO TO NEXT STEP
INSPECT BRAKE BOOSTER PUMP ASSY
1. Disconnect the 2 connectors (A4 and A5) from the brake master cylinder.
2. Connect battery positive (+) lead to BM1 or BM2 terminal and battery negative (-) lead to GND1 or GND2 terminal of the brake master cylinder (pump motor) connector.
  OK:
  
  The operation sound of the pump motor should be heard.
NG : Go to step 6

Fig 1: Inspecting Brake Booster Pump Assy
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP
INSPECT PRESSURE SWITCH(PH)
1. Turn the ignition switch OFF, and depress the brake pedal 40 times or more.
  HINT:
  
  When a pressure in power supply system is released, reaction force becomes lightly.
2. Install the LSPV gauge (SST) to the rear brake caliper and bleed air.
3. While checking the voltage between terminals PH an PHG of brake master cylinder, depress the brake pedal with force of more than 343 N (35 kgf, 77 lbf) and turn the ignition switch ON, then check the rear wheel cylinder pressure when voltage changes from 6 V to 0 V.
  12,553 - 20,104 kpa (128 - 205 kgf.cm ² , 1,820 - 2,916 psi)
  
  Fig 2: Inspecting Pressure Switch (PH)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Turn the ignition switch OFF and disconnect the connector (A4) from the brake master cylinder.
5. While checking the resistance between terminals PH and PHG, depress the brake pedal changing the force in the range of 197 N (20 kgf, 44 lbf) to 343 N (35 kgf, 77 lbf) and check the rear wheel cylinder pressure when resistance changes from 0 kΩ to 1 kΩ between PH and PHG.
  OK:
  
  11,964 - 18,240 kpa (122 - 186 kgf.cm ² , 1,735 - 2,645 psi)
  
  Fig 3: Inspecting Pressure Switch (PHG)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  HINT:
  
  After inspection, connect the connector, fill brake reservoir with brake fluid and clear the DTC (See PRE-CHECK ).
OK : Go to step 4

NG : REPLACE BRAKE MASTER CYLINDER
INSPECT PRESSURE SWITCH(PL)
1. Turn the ignition switch OFF, and depress the brake pedal 40 times or more.
  HINT:
  
  When a pressure in power supply system is released, reaction force becomes lightly.
2. Install the LSPV gauge (SST) to the rear brake caliper and bleed air.
3. Disconnect the connector (A5) from the brake master cylinder.
4. While checking the resistance between terminals PL and PLG of brake master cylinder, depress the brake pedal with force of more than 343 N (35 kgf, 77 lbf) and turn the ignition switch ON, then check the rear wheel cylinder pressure when the resistance changes from 5.7 kΩ to 1.0 kΩ.
  
  Fig 4: Inspecting Pressure Switch (PL)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK:
  
  9,022 - 15,102 kpa (92 - 154 kgf.cm ² , 1,308 - 2,190 psi)
5. Turn the ignition switch OFF and disconnect the connector (A5) from the brake master cylinder.
6. While checking the resistance between terminals PL and PLG of brake master cylinder, depress the brake pedal changing the force in the range of 197 N (20 kgf, 44 lbf) to 343 N (35 kgf, 77 lbf) and check the rear wheel cylinder pressure when resistance changes from 1.0 kΩ to 5.7 kΩ.
  OK:
  
  8,532 - 13,337 kpa (87 - 136 kgf.cm ² , 1,237 - 1,934 psi)
  
  HINT:
  
  After inspection, connect the connector, fill brake reservoir with brake fluid and clear the DTC (See PRE-CHECK ).
NG : REPLACE BRAKE MASTER CYLINDER

OK : GO TO NEXT STEP
CHECK HARNESS AND CONNECTOR(BRAKE MASTER CYLINDER - SKID CONTROL ECU)
1. Check for open and short circuit in harness and connector between terminals PH and PL of the brake master cylinder and skid control ECU (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

OK : CHECK AND REPLACE SKID CONTROL ECU ASSY
CHECK HARNESS AND CONNECTOR(BRAKE MASTER CYLINDER - BRAKE BOOSTER PUMP MOTOR)
1. Check for open and short circuit in harness and connector between brake master cylinder and brake booster pump motor (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
NG : REPLACE BRAKE CONTROL WIRE

OK : GO TO NEXT STEP
INSPECT BRAKE BOOSTER PUMP ASSY
1. Inspect the brake booster pump motor operation.
NG : REPLACE BRAKE BOOSTER PUMP ASSY

OK : REPLACE BRAKE MASTER CYLINDER