DTC B1796 Sleep Operation Failure of Occupant Classification ECU: Description

WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.

During sleep mode, the occupant classification ECU reads the condition of each sensor while the ignition switch is off.

In this mode, if the occupant classification ECU detects an internal malfunction, DTC B1796 is output.

DTC DETECTION CONDITION AND TROUBLE AREA

DTC No.	DTC Detecting Condition	Trouble Area
B1796	Occupant classification ECU malfunction	Occupant classification ECU

CHECK DTC
1. Turn the ignition switch to the ON position.
2. Clear the DTCs stored in memory (See DTC CHECK / CLEAR ).
  HINT:
  
  First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
3. Turn the ignition switch to the LOCK position, and wait for at least 10 seconds.
4. Turn the ignition switch to the ON position.
5. Check the DTCs (See DTC CHECK / CLEAR ).
  OK: DTC B1796 is not output.
  
  HINT:
  
  Codes other than DTC B1796 may be output at this time, but they are not related to this check.
OK : USE SIMULATION METHOD TO CHECK

NG : GO TO NEXT STEP
REPLACE OCCUPANT CLASSIFICATION ECU
1. Turn the ignition switch to the LOCK position.
2. Disconnect the negative (-) terminal cable from the battery.
3. Replace the OCCUPANT CLASSIFICATION ECU (See ).
  HINT:
  
  Perform the inspection using parts from a normal vehicle if possible.
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" (See 1 ).
  OK: The "COMPLETED" is displayed.
PERFORM SENSITIVITY CHECK
1. Using the intelligent tester, perform "Sensitivity check" (See 1 ).
  Standard values: 27 to 33 kg (59.52 to 72.75 lb)
END