Toyota RAV4 (XA40) 2013-2018 Service Manual: Vc output circuit
Description
The ecm constantly generates 5 v power from the battery voltages supplied to
the +b (batt) terminal to
operate the microprocessor. The ecm also provides this power to the sensors
through the vc output
circuit.

When the vc circuit is short-circuited, the microprocessor in the ecm and
sensors that are supplied with
power through the vc circuit are inactivated because the power is not supplied
from the vc circuit. Under
this condition, the system does not start up and the mil does not illuminate
even if the system
malfunctions.
Hint:
Under normal conditions, the mil is illuminated for several seconds when the
ignition switch is first turned
on. The mil goes off when the engine is started.
Wiring diagram

Inspection procedure
- Check mil
- Check that the malfunction indicator lamp (mil) lights
up when turning the ignition switch on.
Ok:
mil lights up

- Check communication between intelligent tester and ecm
- Connect the intelligent tester to the dlc3.
- Turn the ignition switch on and tester on.
- Check the communication between the tester and ecm.


- Check mil (throttle position sensor)
- Disconnect the b3 throttle body connector.
- Turn the ignition switch on.
- Check the mil.

- Reconnect the throttle body connector.

- Check mil (accelerator pedal position sensor)
- Disconnect the a4 accelerator pedal position sensor
connector.
- Turn the ignition switch on.
- Check the mil.

- Reconnect the accelerator pedal position sensor
connector.

- Check mil (canister pump module)

- Disconnect the s3 canister pump module connector.
- Turn the ignition switch on.
- Check the mil.

- Reconnect the canister pump module connector.

- Check mil (battery current sensor)
- Disconnect the b29 battery current sensor connector.
- Turn the ignition switch on.
- Check the mil.

- Reconnect the battery current sensor connector.

- Check harness and connector
- Disconnect the b3 throttle body connector.
- Disconnect the a4 accelerator pedal position sensor
connector.
- Disconnect the s3 canister pump module connector.
- Disconnect the b29 battery current sensor connector.
- Disconnect the a9 and b30 ecm connectors.
- Measure the resistance.
Standard resistance (check for short)

- Reconnect the throttle body connector.
- Reconnect the accelerator pedal position sensor
connector.
- Reconnect the canister pump module connector.
- Reconnect the battery current sensor connector.
- Reconnect the ecm connectors.

Description
When the ignition switch is turned on, the battery voltage is applied to the
igsw of the ecm. The output
signal from the mrel terminal of the ecm causes a current to flow to the coil, ...
Description
When the engine is cranked, the starter relay drive signal output from the
star terminal of the ecm is
input into the sta terminal of the ecm, and ne signal generated by the
cranksha ...
Other materials:
Front passenger side seat belt warning light malfunction
Description
When the ignition switch is on, the center airbag sensor transmits front seat
inner belt status signals to
the combination meter through the can bus line. If the front passenger seat belt
is not fastened, the
heater control panel (automatic a/c) or clock (manual a/c) blinks the fr ...
Wireless remote control/electronic key battery
Replace the battery with a
new one if it is depleted.
â– If the key battery is depleted
The following symptoms may occur:
The smart key system (if
equipped) and wireless remote
control will not function properly.
The operational range will be
reduced.
Items to prepare
Prepare the following be ...
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 ...