Inspection Procedure

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Start the inspection from step 1 in case of using the TOYOTA hand-held tester and start from step 3 in case of not using the TOYOTA hand-held tester.

Check Output Value Of The Master Cylinder Pressure Sensor No. 1 And No. 2.
Preparation :
1. Connect the TOYOTA hand-held tester to the DLC3.
2. Turn the ignition switch ON, and push the TOYOTA hand-held tester main switch ON.
3. Select the DATALIST mode on the TOYOTA hand-held tester.
Check : That the brake fluid pressure value of the master cylinder pressure sensor displayed on the TOYOTA hand-held tester is changing when depressing the brake pedal.

OK : Brake fluid pressure value must be changing.
1. OK : Check and replace skid control ECU.
  NOTE: When replacing the ECU, perform the zero point calibration. See step 6 under PRE-CHECK.
2. NG : Go to step 2.
Is Pedal Lowered Or Spongy ?
1. YES : BLEEDING BRAKE SYSTEM .
2. NO : Go to step 3.
Check Master Cylinder Pressure Sensor No. 1 and No. 2.
Preparation : Install LSPV gauge to the front brake caliper bleeder plug portion, and bleed air from LSPV gauge.

SST 09709-29018

Master cylinder pressure sensor No. 1

Check : Start the engine and depress the brake pedal, then check the relation between the fluid pressure and voltage of PMC and E1 terminals of the master cylinder pressure sensor No. 1 with connector still connected.

OK: See Fig 1 for specification.

Fig 1: Identifying Front Brake Caliper Fluid Pressure & Voltage Relationship
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT: Voltage between terminals VCM and E1: 4.7-5.3 V

Fig 2: Locating PMC, VCM & E1
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Master cylinder pressure sensor No. 2

Check : Start the engine and depress the brake pedal, then check the relation between the fluid pressure and voltage of PMC2 and E2 terminals of the master cylinder pressure sensor No. 2 with connector still connected.

HINT: Voltage between terminals VCM2 and E2: 4.7-5.3 V

Fig 3: Locating PMC2, VCM2 & E2
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : See Fig 1 for specification.
1. NG : Replace master cylinder pressure sensor.
2. OK : Go to step 4.
Check For Open And Short Circuit In Harness And Connector Between Master Cylinder Pressure Sensor And Skid Control ECU. See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE .
1. NG : Repair or replace harness or connector.
2. OK : Go to next step.
Check Whether Or Not The ECU Terminal STP Input Voltage Is Changed When The Stop Light Switch Is Turned On And Off.
1. NO : Check stop light switch circuit. See DTC C1249/49 Stop Light Switch Circuit .
2. YES : Check and replace skid control ECU.