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Description
The battery supplies electricity to the ecm even when the ignition switch is in the off position. This power allows the ecm to store data such as dtc history, freeze frame data and fuel trim values. If the battery voltage falls below a minimum level, the memory is cleared and the ecm determines that there is a malfunction in the power supply circuit. When the engine is next started, the ecm illuminates the mil and sets the dtc.

Hint:
If dtc p0560 is set, the ecm does not store other dtcs or the data stored in the ecm are partly erased.
Monitor strategy

Typical enabling conditions
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Typical malfunction thresholds
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Wiring diagram

Inspection procedure
Hint:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
Standard resistance:
below 1

Standard resistance (check for open)

Standard resistance (check for short)


Standard resistance (check for open)

Standard resistance (check for short)


Ok: battery is not depleted

Ok: battery terminals are not loose or corroded



Battery temperature sensor circuit
Internal control module random access memory (ram) errorInstallation
Install fuel filler opening lid lock retainer
Install the lock retainer and turn it counterclockwise
as shown in the illustration.
Install fuel filler opening lid lock retainer
Install the cable and turn it clockwise as shown in
the illustration.
Install the fuel l ...
Disposal
Hint:
When scrapping a vehicle equipped with srs or disposing of
the front seat side airbag, be sure to deploy the airbag first in
accordance with the procedure described below. If any
abnormality occurs with the airbag deployment, contact the
service dept. Of toyota motor sales, u.S.A., Inc.
...
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
conditioning amplifier and
servo motors.
Wiring diagram
Inspection procedure
Inspect fuse (ec ...