Toyota Sienna Service Manual: Brake Switch "B" Circuit High
DESCRIPTION
The purpose of this circuit is to prevent the engine from stalling while driving in lock-up condition when brakes are suddenly applied.
When the brake pedal is depressed, this switch sends a signals to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.
MONITOR DESCRIPTION
This DTC indicates that the stop light switch remains on. When the stop light switch remains ON during "stop and go" driving, the ECM interprets this as a fault in the stop light switch and the MIL comes on and the ECM stores the DTC. The vehicle must stop (less than 3 km/h (2 mph)) and go (30 km/h (19 mph) or more) 5 times for two driving cycles in order to detect a malfunction.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
WIRING DIAGRAM
INSPECTION PROCEDURE
1 READ VALUE OF DATA LIST
HINT: Using the intelligent tester to read the DATA LIST allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This nonintrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the DATA LIST information early in troubleshooting is one way to save diagnostic time.
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect the OBD II scan tool or intelligent tester together with the CAN VIM (controller area network vehicle interface module) to the DLC3.
(d) Turn the ignition switch to the ON position.
(e) Turn on the tester.
(f) Select the item "DIAGNOSIS / ENHANCED OBD II / DATA LIST".
(g) According to the display on the tester, read the "DATA
LIST". 
| NOTICE: In the table below, the value listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether apart is faulty or not. |
Result 
2 INSPECT STOP LIGHT SWITCH ASSEMBLY
(a) Remove the stop light switch assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance
3 CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)
(a) Install the stop light switch assembly.
(b) Measure the voltage according to the value(s) in the table below when the brake pedal is depressed and released.
Standard voltage
REPLACE ECM
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DESCRIPTION
This sensor detects the rotation speed of the input turbine. By comparing the
input turbine speed signal
(NT) with the counter gear speed sensor signal (NC), the ECM detects the sh ...
Torque Converter Clutch Solenoid Performance
(Shift Solenoid Valve DSL)
SYSTEM DESCRIPTION
The ECM uses the signals from the throttle position sensor, air-flow meter,
turbine (input) speed sensor,
intermediate (counter) shaft speed sensor and crankshaft position s ...
Other materials:
Rear Occupant Classification Sensor RH Circuit
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DTC B1783 Rear Occupant Classification Sensor RH Circuit
Malfunction
DESCRIPTION
The rear occupant classification sensor RH circuit consists of the occupant
classification ECU and the
rear occupant classification sensor RH.
DTC B1783 is recorded when a malfunction is detected in the rear oc ...
Front Airbag Sensor LH Circuit Malfunction
DTC B1149/37 Front Airbag Sensor LH Circuit Malfunction
DESCRIPTION
The front airbag sensor LH circuit consists of the center airbag sensor
assembly and front airbag sensor
LH.
If the center airbag sensor assembly receives signals from the front airbag
sensor LH, it judges whether or
not ...
Things you should know
If you notice any symptoms
If you notice any of the following symptoms, refer to the likely cause
and the solution, and re-check.
If the symptom is not resolved by the solution, have the vehicle
inspected by your Toyota dealer.
Likely cause
Solution
The ima ...