Toyota RAV4 manuals

Toyota Sienna Service Manual: 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).

DTC B1794 is recorded when a malfunction is detected in the occupant classification ECU or the power source circuit.

HINT: When DTC B1794 is output after switching the ignition switch LOCK-ON-LOCK 50 times in a row when a malfunction occurs in the power circuit for the occupant classification system, the DTC is output again when a malfunction is detected even once after being cleared, unless the normal system code is

DTC No.

DTC Detecting Condition

Trouble Area

B1794

  • The ignition switch is turned from LOCK to ON, hold for 10 seconds or more, and back to LOCK again 50 times in a row when a malfunction occurs in the power circuit for the occupant classification system.
  • Occupant classification ECU malfunction
  • Battery
  • ECU-B Fuse
  • Floor wire No. 2
  • Front seat wire RH
  • Occupant classification ECU

WIRING DIAGRAM

WIRING DIAGRAM

INSPECTION PROCEDURE

1 CHECK BATTERY

  1. Measure the voltage of the battery.

    Standard: 11 to 14 V

2 CHECK FUSE

  1. Check the ECU-B fuse.

    Standard: Below 1 Ω

3 CHECK WIRE HARNESS

CHECK WIRE HARNESS

  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 and resistance 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 and resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

4 CHECK DTC

  1. Turn the ignition switch to the ON position.

    (b) Clear the DTCs stored in memory (35).

    HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.

  2.  Turn the ignition switch to the LOCK position.
  3.  Turn the ignition switch to the ON position, and wait for at least 10 seconds.
  4.  Using the intelligent tester, check the DTCs of the occupant classification ECU (35).

OK: DTC B1794 is not output. HINT: Codes other than code B1794 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

5 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

6 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 the "Zero point calibration" (28).

OK: The "COMPLETED" is displayed.

7 PERFORM SENSITIVITY CHECK

  1. Using the intelligent tester, perform the "Sensitivity check"

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

END

Occupant Classification Sensor Power Supply Circuit Malfunction
DTC B1793 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 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 ...

Other materials:

Inspection
1. INSPECT BRAKE VACUUM CHECK VALVE ASSEMBLY (a) Check the vacuum check valve. (1) Slide the clip and disconnect the vacuum hose. (2) Remove the vacuum check valve. (3) Check that there is ventilation from the booster to the engine, and no ventilation from the engine to the booster. ...

Low pitched horn
COMPONENTS REMOVAL 1. REMOVE FRONT BUMPER COVER ET-3 2. REMOVE LOW PITCHED HORN  Disconnect the connector.  Remove the bolt and horn. INSPECTION 1. INSPECT LOW PITCHED HORN  Apply battery voltage and check operation of the horn, as shown in the table. Stan ...

Rear combination light assembly
COMPONENTS REMOVAL 1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL 2. REMOVE REAR COMBINATION LIGHT ASSEMBLY  Remove the 2 bolts.  Disengage the 2 pins and separate the rear combination light assembly as shown in the illustration.  Disconnect the connector a ...

В© 2011-2019 Copyright www.tsienna.net