Toyota RAV4 (XA40) 2013-2018 Service Manual: Center airbag sensor assembly communication circuit malfunction
Description
The center airbag sensor communication circuit consists of the occupant classification ecu and the center airbag sensor.
Dtc b1790 is recorded when a malfunction is detected in the center airbag sensor communication circuit.
Wiring diagram
Inspection procedure
Hint:
- If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to see the undersurface of the seat cushion.
- In the above case, hold the seat so that it does not tip over. Holding the seat for a long period of time may cause a problem, such as seat rail deformation. Hold the seat up only for as long as necessary.
- Check for dtc
- Turn the ignition switch on.
- Clear the dtcs (see page rs-249).
Hint:
First clear dtcs stored in the occupant classification ecu and then in the center airbag sensor.
- Turn the ignition switch off.
- Turn the ignition switch on.
- Check the dtcs (see page rs-249).
Ok: dtc b1790 is not output.
Hint:
Dtcs other than dtc b1790 may be output at this time, but they are not related to this check.
- Check connection of connector
- Turn the ignition switch off.
- Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
- Check that the connectors are properly connected to the occupant classification ecu and the center airbag sensor.
Ok: the connectors are properly connected.
- Check floor wire (to b+)
- Disconnect the connectors from the occupant classification ecu and the center airbag sensor.
- Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
- Turn the ignition switch on.
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Check floor wire (for open)
- Turn the ignition switch off.
- Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
- Using a service wire, connect terminals l6-12 (fsp+) *1 and l6-13 (fsp-) *1 or l7-16 (fsp+) *2 and l7-24 (fsp-) *2 of connector b.
Notice:
Do not forcibly insert a service wire into the terminals of the connector when connecting them.
- Measure the resistance of the wire harness side connector.
Standard resistance
Hint:
*1: W/o curtain shield airbag
*2: W/ curtain shield airbag
- Check floor wire (for short)
- Disconnect the service wire from connector b.
- Measure the resistance of the wire harness side connector.
Standard resistance 
- Check floor wire (to ground)
- Measure the resistance of the wire harness side connector.
Standard resistance 
- Check for dtc
- Connect the connectors to the occupant classification ecu and the center airbag sensor.
- Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
- Turn the ignition switch on.
- Clear the dtcs (see page rs-249).
Hint
First clear dtcs stored in the occupant classification ecu and then in the center airbag sensor.
- Turn the ignition switch off.
- Turn the ignition switch on.
- Check the dtcs (see page rs-249).
Ok: dtc b1790 is not output.
Hint:
Dtcs other than dtc b1790 may be output at this time, but they are not related to this check.
- Replace occupant classification ecu
- Turn the ignition switch off.
- Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
- Replace the occupant classification ecu (see page rs- 392).
Hint:
Perform the inspection using parts from a normal vehicle if possible.
- Perform zero point calibration
- Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
- Connect the intelligent tester (with can vim) to the dlc3.
- Turn the ignition switch on.
- Using the intelligent tester, perform the zero point calibration (see page rs-241).
Ok: completed is displayed.
- Perform sensitivity check
- Using the intelligent tester, perform the sensitivity check (see page rs-241).
Standard value: 27 to 33 kg (59.52 To 72.75 Lb)
- Check for dtc
- Turn the ignition switch on.
- Clear the dtcs (see page rs-249).
Hint:
First clear dtcs stored in the occupant classification ecu and then in the center airbag sensor.
- Turn the ignition switch off.
- Turn the ignition switch on.
- Check the dtcs (see page rs-249).
Ok: dtc b1790 is not output.
Hint:
Dtcs other than dtc b1790 may be output at this time, but they are not related to this check.
End
Rear occupant classification sensor rh collision detection
Description
Dtc b1788 is output when the occupant classification ecu receives a collision
detection signal sent by
the rear occupant classification sensor rh when an accident occurs.
Dtc b1 ...
Occupant classification sensor power supply circuit malfunction
Description
The occupant classification sensor power supply circuit consists of the
occupant classification ecu and
the occupant classification sensors.
Dtc b1793 is recorded when a malfunc ...
Other materials:
Steering angle sensor circuit malfunction
Description
The steering sensor signal is sent to the skid control ecu via the can
communication system. When
there is a malfunction in the can communication system, it is detected by the
steering sensor zero point
malfunction diagnostic function.
Wiring diagram
Inspection proce ...
Steering angle sensor zero point malfunction
Description
The skid control ecu learns the steering sensor zero point every time the
ignition switch is turned on and
the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds.
The ecu also stores the
previous zero point.
If front wheel alignment or the steering wh ...
On-vehicle inspection
Check throttle body
Check the throttle control motor operating sounds.
Turn the ignition switch on.
When pressing the accelerator pedal, check
the operating sound of the running motor. Make
sure that no friction noises emit from the motor.
If friction noise exists, replace t ...
