Toyota Sienna Service Manual: Master Cylinder Pressure Sensor Malfunction
DTC C1246/46 Master Cylinder Pressure Sensor Malfunction
DESCRIPTION
Master cylinder pressure sensor is connected to the skid control ECU in the actuator.
INSPECTION PROCEDURE
1 READ VALUE ON INTELLIGENT TESTER (MASTER CYLINDER PRESSURE SENSOR)
(a) Connect the intelligent tester to the DLC3.
(b) Start the engine.
(c) Select the DATA LIST mode on the intelligent tester.
ABS / VSC: 
(d) Check that the brake fluid pressure value of the master cylinder pressure sensor indicated on the intelligent tester, changes when the brake pedal is depressed.
OK: Brake fluid pressure value should change.
NOTICE: When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
REPLACE BRAKE ACTUATOR ASSEMBLY
2 INSPECT SKID CONTROL ECU (STP1 TERMINAL)
(a) Disconnect the skid control ECU connector.
(b) Measure the voltage according to the value(s) in the table below
Standard voltage
NOTICE: When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
REPLACE BRAKE ACTUATOR ASSEMBLY
Low Battery Positive Voltage
DTC C1241/41 Low Battery Positive Voltage
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT ECU-IG FUSE
(a) Remove the ECU-IG fuse from the driver side J/B.
(b) Check continu ...
Open in Stop Light Switch Circuit
DTC C1249/49 Open in Stop Light Switch Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK STOP LIGHT SWITCH OPERATION
(a) Check that the stop light comes on when the brak ...
Other materials:
Symptom confirmation and diagnostic trouble code
HINT:
The diagnostic system in the SIENNA has various
functions.
The first function is the Diagnostic Trouble Code
(DTC) check. A DTC is a code stored in the ECU
memory whenever a malfunction in the signal circuits
to the ECU occurs. In a DTC check, a previous
malfunction's DTC can be ...
Indicator Circuit
DESCRIPTION
The indicator displays the location of the obstacle and the approximate
distance between the vehicle and
the obstacle either by blinking or turning on.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU - AIR CONDITIONER
AMPLIFIER)
...
How to proceed with
troubleshooting
1 VEHICLE BROUGHT TO WORKSHOP
2 CUSTOMER PROBLEM ANALYSIS
3 CHECK INITIAL CHECK FUNCTION
4 PROBLEM SYMPTOMS TABLE
THE CORRESPONDING SYSTEM DOES NOT EXIST (Go to step 5)
5 BASED ON THE MALFUNCTION SYMPTOM, PERFORM THE TROUBLESHOOTING
BELOW
Operation check (C).
Terminals of ECU
6 ...