Toyota RAV4 manuals

Toyota Sienna Service Manual: Occupant Classification ECU Malfunction

DTC B1795 Occupant Classification ECU Malfunction

DESCRIPTION

DTC B1795 is recorded when a malfunction is detected in the occupant classification ECU.

Troubleshoot DTC B1771 first when the DTCs B1771 and B1795 are output simultaneously.

DTC No.

DTC Detecting Condition

Trouble Area

B1795

  • Occupant classification ECU circuit malfunction
  •  The occupant classification ECU receives a short circuit to ground signal in the passenger side buckle switch circuit for 2 seconds.
  •  Occupant classification ECU malfunction
  • Front seat wire RH
  •  Front seat inner belt assembly RH (Passenger side buckle switch)
  •  Occupant classification ECU

INSPECTION PROCEDURE

1 CHECK DTC

  1. Turn the ignition switch to the ON position, and wait for at least 10 seconds.
  2.  Check the DTCs (35).

Result:
A:
DTC B1795 is output.

B:
DTCs B1771 and B1795 are output.

HINT: Codes other than DTC B1771 and B1795 may be output at this time, but they are not related to this check.

2 CHECK FUSE

  1. Measure the resistance of the ECU-B fuse.

    Resistance: Below 1 Ω

3 CHECK WIRE HARNESS (SOURCE VOLTAGE)

 CHECK WIRE HARNESS (SOURCE VOLTAGE)

  1. Turn the ignition switch to the LOCK position.
  2.  Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
  3.  Disconnect the connector from the occupant classification ECU.
  4.  Connect the negative (-) terminal cable to the battery.
  5.  Turn the ignition switch to the ON position.
  6.  Measure the voltage according to the value(s) in the table below.

Standard voltage

Standard voltage

  1. Turn the ignition switch to the LOCK position.
  2.  Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

4 REPLACE OCCUPANT CLASSIFICATION ECU

  1. Turn the ignition switch to the LOCK position.
  2.  Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
  3.  Replace the occupant classification ECU

5 PERFORM ZERO POINT CALIBRATION

  1. Connect the negative (-) terminal cable to the battery.
  2.  Connect the intelligent tester to the DLC3.
  3.  Turn the ignition switch to the ON position.
  4.  Using the intelligent tester, perform "Zero point calibration" (28).

OK: "COMPLETED" is displayed.

6 PERFORM SENSITIVITY CHECK

  1. Using the intelligent tester, perform "Sensitivity check" (28).

Standard value: 27 to 33 kg (59.52 to 72.75 lb)

END

Open in Occupant Classification ECU Battery Positive Line
DTC B1794 Open in Occupant Classification ECU Battery Positive Line DESCRIPTION This circuit consists of the occupant classification ECU and the power source circuit (battery, fuse, wire harness ...

Sleep Operation Failure of Occupant Classification ECU
DTC B1796 Sleep Operation Failure of Occupant Classification ECU DESCRIPTION During sleep mode, the occupant classification ECU reads the condition of each sensor while the ignition switch is of ...

Other materials:

Diagnosis system
1. CHECK DLC3  The ECU uses ISO 15765-4 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and meets the ISO 15765-4 format. NOTICE: *: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition s ...

Rear Occupant Classification Sensor RH Circuit Malfunction
DTC B1783 Rear Occupant Classification Sensor RH Circuit Malfunction DESCRIPTION The rear occupant classification sensor RH circuit consists of the occupant classification ECU and the rear occupant classification sensor RH. DTC B1783 is recorded when a malfunction is detected in the rear oc ...

Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown. If this happens, check and replace the fuses as necessary. Turn the engine switch to the “LOCK” position (vehicles without a smart key system) or off (vehicles with a smart key system). Open the fuse box cover. ...

© 2011-2021 Copyright www.tsienna.net