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:
Circuit opening relay
On-vehicle inspection
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Inspect instrument panel junction block
Notice:
Th ...
Fuel tank
Components
Removal
Discharge fuel system pressure (see page
fu-9)
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
...
Intake air temperature sensor gradient too high
Description
The intake air temperature (iat) sensor, mounted on the mass air flow (maf)
meter, monitors the iat.
The iat sensor has a built-in thermistor with a resistance that varies according
to the temperature of the
intake air. When the iat is low, the resistance of the thermist ...
