Toyota RAV4 (XA40) 2013-2018 Service Manual: Ecu power source circuit
Description
This is the power source for the tire pressure warning ecu.
Wiring diagram
Inspection procedure
Notice:
It is necessary to register an id code after replacing the tire pressure monitor valve and/or the tire pressure warning ecu (see page tw-9).
- Inspect fuse (ecu-ig1)
- Remove the ecu-ig1 fuse from the instrument panel junction block.
- Measure the resistance of the fuse.
Standard resistance:
below 1 
- Inspect ig1 relay
- Remove the ig1 relay from the instrument panel junction block.
- Measure the resistance of the relay.
Standard resistance
- Inspect wire harness (ecu - battery and body ground)
- Disconnect the e56 ecu connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Measure the resistance of the wire harness side connector.
Standard resistance 
Proceed to next circuit inspection shown in problem symptoms table
Tire pressure warning light circuit
Description
If the tire pressure warning ecu detects trouble, the tire pressure warning
light turns on and tire pressure
monitor is canceled at the same time. At this time, the ecu records a dtc i ...
Tire pressure warning receiver (w/ antenna)
Components
...
Other materials:
Solar sensor circuit (driver side)
Description
The solar sensor, which is installed on the upper side of the instrument
panel, detects sunlight and
controls the air conditioning auto mode. The output voltage from the solar
sensor varies in accordance
with the amount of sunlight. When the sunlight increases, the output volt ...
System description
Engine immobiliser system description
The engine immobiliser system is designed to prevent
the vehicle from being stolen. This system uses a
transponder key ecu that stores the key codes of
authorized ignition keys. If an attempt is made to start
the engine using an unauthorized key, the e ...
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 ...
