Inspection Procedure

HINT:

Start the inspection from step 1 when using the hand-held tester and start from step 3 when not using the hand-held tester.

1. PERFORM ACTIVE TEST BY HAND-HELD TESTER (H/B MOTOR RELAY) 
   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch to the ON position and push the hand-held tester main switch ON.
   3. Start the engine.
   4. Select "ACTIVE TEST" mode on the hand-held tester.
      ACTIVE TEST REFERENCE CHART
      
      

      Item	Vehicle Condition/Test Details	Diagnostic Note
      H/B MOT RELAY	Turns H/B motor relay ON/OFF	Operation sound of motor can be heard

   5. Check operation sound of the H/B motor individually when operating it with the hand-held tester.

      OK: 

      The operation sound of the H/B motor can be heard. 

   1. NG: Go to step 2 
   2. OK: Go to step   4 
2. INSPECT SKID CONTROL ECU (+BM TERMINAL VOLTAGE) 
   1. Disconnect the skid control ECU connectors.
   2. Turn the ignition switch to the ON position.
   3. Measure the voltage according to the value(s) in the table below.

      Standard: 

      TESTER CONNECTION AND SPECIFIED CONDITION (1 OF 2)
      
      

      Tester Connection	Specified Condition
      S28-2 (+BM1) - Body ground	10 to 14 V
      S29-2 (+BM2) - Body ground	10 to 14 V

      Fig 1: Identifying Skid Control ECU +BM Terminal

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM CIRCUIT) 
   2. OK: GO TO NEXT STEP 
3. INSPECT SKID CONTROL ECU (GND TERMINAL CONTINUITY) 
   1. Measure the resistance according to the value(s) in the table below.

      Standard: 

      TESTER CONNECTION AND SPECIFIED CONDITION (2 OF 2)
      
      

      Tester Connection	Specified Condition
      S28-1 (GND1) - Body ground	Below 1 Ω
      S28-32 (GND2) - Body ground	Below 1 Ω
      S29-4 (GND3) - Body ground	Below 1 Ω

      Fig 2: Identifying Skid Control ECU GND Terminal

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 
   2. OK: GO TO NEXT STEP 
4. RECONFIRM DTC 

1. Clear the DTC (see DTC CHECK/CLEAR  ).
2. Turn the ignition switch off.
3. Depress the brake pedal more than 20 times.
4. Turn the ignition switch to the ON position.
5. Wait until the pump motor stops.
6. Depress the brake pedal several times until the pump motor turns on.
7. Wait until the pump stops.
8. Repeat (f) and (g) 3 more times.
9. Check if the same DTC is detected (see DTC CHECK/CLEAR  ).

   HINT:

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

   Result: 

   Fig 3: Result Description Chart

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. B: END 
2. A: REPLACE HYDRAULIC BRAKE BOOSTER (SEE  OVERHAUL  )