Toyota RAV4 Service Manual: System voltage
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
Typical malfunction thresholds
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.
- Check fuse (efi main and p/i)
- Remove the efi main fuse and p/i fuse from the engine room no. 1 Relay block.
- Measure the resistance of the efi main fuse and p/i fuse.
Standard resistance:
below 1 
- Reinstall the efi main fuse and p/i fuse.
- Check harness and connector (ecm - efi main fuse, efi main fuse - battery)
- Check the harness and the connector between the efi main fuse and ecm.
- Remove the efi main fuse from the engine no. 1 Room relay block.
- Disconnect the a9 ecm connector.
- Measure the resistance.
Standard resistance (check for open)
Standard resistance (check for short)
- Reconnect the ecm connector.
- Reinstall the efi main fuse.
- Check the harness and the connector between the efi main fuse and battery.
- Remove the efi main fuse from the engine room no. 1 Relay block.
- Disconnect the positive battery terminal.
- Check the resistance.
Standard resistance (check for open)
Standard resistance (check for short)
- Reconnect the positive battery terminal.
- Reinstall the efi main fuse.
- Inspect battery
- Check that the battery is not depleted.
Ok: battery is not depleted
- Check battery terminal
- Check that the battery terminals are not loose or corroded.
Ok: battery terminals are not loose or corroded
- Check whether dtc output recurs
- Connect the intelligent tester to the dlc3.
- Turn the ignition switch on and turn the tester on.
- Clear dtcs (see page es-35).
- turn the ignition switch off and turn the tester off.
- Start the engine and turn the tester on.
- Select the following menu items: diagnosis / enhanced obd ii / dtc info / current codes.
- Read dtcs.
Battery temperature sensor circuit
Description
The battery temperature sensor installed on the battery current sensor
detects battery temperature.
A thermistor is integrated into the battery temperature sensor, and the
...
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
...
Other materials:
Pressure control solenoid "A " performance (shift solenoid valve sl1)
Description
The ecm uses signals from the vehicle speed sensor to detect the actual gear
position (1st, 2nd, 3rd or
o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory
to detect mechanical
problems of the shift solenoid valves, valve body or automatic ...
Rear window and outside rear view mirror defoggers
These features are used to defog the rear window, and to
remove raindrops, dew and frost from the outside rear view mirrors
(if equipped).
Vehicles with a manual air conditioning system
On/off
The defoggers will automatically
turn off after approximately 15 minutes.
Vehicles with an au ...
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)
...
