Toyota RAV4 (XA40) 2013-2018 Service Manual: Downhill assist control operation switch (test mode dtc)
Description
The downhill assist control switch is connected to the skid control ecu in the abs and traction actuator.
Dtc c1379/74 can be detected when the downhill assist control switch sends the downhill assist control switch signal or test mode ends. Dtc c1379/74 is output only in test mode.
Wiring diagram
Refer to downhill assist control switch circuit (see page bc-157).
Inspection procedure
Notice:
When replacing the abs and traction actuator, perform zero point calibration (see page bc-24).
- Check wire harness (skid control ecu - body ground)
- Disconnect the a19 ecu.
- Measure the resistance of the wire harness side connector.
Standard resistance 
- Inspect downhill assist control switch
- Remove the downhill assist control switch.
- Measure the resistance of the switch.
Standard resistance 
- Check wire harness (skid control ecu - downhill assist control switch)
- Disconnect the a19 ecu connector.
- Disconnect the e31 switch connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance 
Replace abs and traction actuator assembly
Stop light control relay malfunction
Description
The skid control ecu inputs the stop light switch signal and detects the status of the brake operation.
Wiring diagram
Inspection procedure
Notice:
When replacing the abs and traction actuator, perform zero point calibration (see page bc-24).
- Check stop light (operation)
- Check that the light illuminates when the brake pedal is depressed, and turns off when the brake pedal is released.
Ok 
- Check wire harness (skid control ecu - battery)
- Disconnect the a19 ecu connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Check wire harness (skid control ecu)
- Disconnect the a19 ecu connector.
- Measure the resistance of the wire harness side connector
Standard resistance 
- Perform active test by intelligent tester (stop light relay)
- Select the active test, generate a control command, and then check that the stop light relay operates.
Ok: the stop lights illuminate or turn off.
- Reconfirm dtc
- Clear the dtc (see page bc-47).
- Start the engine.
- Drive the vehicle at a speed of 5 km/h (3 mph) or more for several seconds.
- Check if the same dtc is output (see page bc-47).
Result 
Replace abs and traction actuator assembly
- Inspect stop light control relay (marking: brk)
- Remove the stop light control relay from the engine room no. 1 Relay block.
- Measure the resistance of the relay.
Standard resistance 
- Check wire harness (engine room no. 1 Relay block - skid control ecu and battery)
- Remove the stop light control relay.
- Disconnect the a19 ecu connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Measure the resistance of the wire harness side connector.
Standard resistance 
- Reconfirm dtc
- Clear the dtc (see page bc-47).
- Start the engine.
- Drive the vehicle at a speed of 5 km/h (3 mph) or more for several seconds.
- Check if the same dtc is output (see page bc-47).
Result 
Replace abs and traction actuator assembly
- Check wire harness (stop light switch - battery)
- Disconnect the a3 switch connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Inspect stop light switch assembly
- Remove the stop light switch connector.
- Measure the resistance of the switch.
Standard resistance 
- Check wire harness (stop light switch - stop light control relay)
- Disconnect the a3 switch connector.
- Remove the stop light control relay.
- Measure the resistance of the wire harness side connectors.
Standard resistance 
- Inspect stop light control relay (marking: brk)
- Remove the stop light control relay from the engine room no. 1 Relay block.
- Measure the resistance of the relay.
Standard resistance 
- Check wire harness (stop light and rear combination light - control relay)
- Disconnect the q1, k12 and k14 light connectors.
- Remove the stop light control relay.
- Measure the resistance of the wire harness side connectors.
Standard resistance 
Check for intermittent problems
Different diameter tire malfunction
Description
The skid control ecu measures the speed of each wheel by receiving signals
from the speed sensor.
These signals are used for recognizing that all 4 wheels are operating properly. ...
Control module communication bus off
Description
Inspection procedure
The skid control ecu inputs the signals from the ecm, steering angle sensor,
and yaw rate and
acceleration sensor via can communication system.
Ch ...
Other materials:
Ambient temperature sensor circuit
Description
The ambient temperature sensor is installed in the front part of the
condenser to detect the ambient
temperature and control the air conditioner. The sensor is connected to the
combination meter and
detects fluctuations in the ambient temperature. This data is used for
contr ...
Diagnostic trouble code chart
If a dtc is displayed during the dtc check, check the circuit
listed for the dtc in the table below (refer to the appropriate
page).
Hint:
When the srs warning light remains on and the normal
system code is output, a decrease in the source voltage is
likely to occur. This malfunction is n ...
Utility vehicle
precautions
This vehicle belongs to the utility vehicle class, which has
higher ground clearance and narrower tread in relation to the
height of its center of gravity to make it capable of performing in
a wide variety of off-road applications.
Utility vehicle feature
Specific design characteristics give ...
