Toyota RAV4 (XA40) 2013-2018 Service Manual: Brake switch "A" / "B" correlation
Description
The stop light switch is a duplex system that transmits two signals: stp and st1-. These two signals are used by the ecm to monitor whether or not the brake system is working properly. If the signals, which indicate the brake pedal is being depressed and released, are detected simultaneously, the ecm interprets this as a malfunction in the stop light switch and sets the dtc.
Hint:
The normal conditions are as shown in the table below. The signals can be read using the intelligent tester.
Wiring diagram
Inspection procedure
Hint:
- Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- Stp signal conditions can be checked using the intelligent tester.
- Connect the intelligent tester to the dlc3.
- Turn the ignition switch on.
- Turn the tester on.
- Select the following menu items: diagnosis / enhanced obd ii / data list / primary / stop light sw.
- Check the stp signal when the brake pedal is depressed and released.
- Check stop light switch assembly (terminal b voltage)
- Disconnect the a3 stop light switch connector.
- Turn the ignition switch on.
- Measure the voltage between the terminals of the a3 stop light switch connector and body ground.
Standard voltage 
- Reconnect the stop light switch connector.
- Inspect stop light switch assembly
- Remove the stop light switch.
- Check the resistance.
Standard resistance
- Reinstall the stop light switch.
- Check ecm (stp and st1 - voltage)
- Disconnect the a9 ecm connector.
- Turn the ignition switch on.
- Measure the voltage between the terminals st1- and stp of the a9 ecm connector and body ground.
standard voltage 
- Reconnect the ecm connector.
- Inspect fuse (stop and ign fuse)
- Remove the stop and ign fuses from the instrument panel junction block.
- Measure the resistance.
Standard resistance:
below 1 
- Reinstall the stop and ign fuses.
Vehicle speed sensor "A"
description
The speed sensor detects the wheel speed and sends the appropriate signals to
the skid control ecu.
The skid control ecu converts these wheel speed signals into a 4-pulse signal ...
Idle control system malfunction
Description
The idling speed is controlled by the etcs (electronic throttle control
system). The etcs is comprised
of: 1) the one valve type throttle body; 2) the throttle actuator, which
op ...
Other materials:
General maintenance (2006/01- )
Inspect steering linkage and gear housing
Check the steering wheel free play.
Check the steering linkage for looseness or
damage.
Check that the tie rod ends do not have
excessive play.
Check that the dust seals and boots are not
damaged.
Check that the boot clamps are not ...
Problem symptoms table
Hint:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms
are listed in order of probability in the "suspected area"
column of the table. Check each symptom by checking the
suspected areas in the order they are listed. Re ...
Freeze frame data
Description
Freeze frame data records the engine conditions (fuel
system, calculated load, engine coolant temperature,
fuel trim, engine speed, vehicle speed, etc.) When a
malfunction is detected. When troubleshooting, it can
help determine if the vehicle was running or stopped, the
engin ...
