Toyota RAV4 Service Manual: Back-up power source circuit
Description
This is the back-up power source circuit for the air conditioning amplifier. Power is supplied even when the ignition switch is turned off and is used for functions such as the diagnostic trouble code memory.
wiring diagram
Inspection procedure
- Inspect fuse (ecu-b2)
- Remove the ecu-b2 fuse from the engine room no. 2 Relay block.
- Measure the resistance of the fuse.
Standard resistance:
below 1 
- Check wire harness (air conditioning amplifier - battery)
- Disconnect the e37 amplifier connector.
- Measure the voltage of the wire harness side connector.
Standard voltage
- Check wire harness (air conditioning amplifier - body ground)
- Disconnect the e37 amplifier connector.
- Measure the resistance of the wire harness side connector.
Standard resistance
Proceed to next circuit inspection shown in problem symptoms table
Ig power source circuit
Description
This is the main power source supplied to the air conditioning amplifier when
the ignition switch is on
(ig). This power source is used for operating components, such as the air
cond ...
Other materials:
Check and replace ecu
Notice:
The connector should not be disconnected from
the ecu. Perform the inspection from the
backside of the connector on the wire harness
side.
When no measuring condition is specified,
perform the inspection with the engine stopped
and the ignition switch on.
Check that the con ...
Internal control module random access memory (ram) error
Description
The ecm continuously monitors its own internal memory status, internal
circuits, and output signals
transmitted to the throttle actuator. This self-check ensures that the ecm is
functioning properly. If any
malfunction is detected, the ecm sets the appropriate dtc and illumina ...
Registration
Hint:
The key has 2 codes: the key code (immobiliser code) and
the wireless code (recognition code). Both of these codes
need to be registered. For wireless code registration
procedures, refer to the following procedures (see page dl-
46). For key code registration procedures, refer to the
pro ...