Toyota Tundra Service Manual: Occupant Classification ECU Malfunction (B1795)

Toyota Tundra Service Manual / Vehicle Interior / Supplemental Restraint Systems / Occupant Classification System / Occupant Classification ECU Malfunction (B1795)

DESCRIPTION

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

Troubleshoot DTC B1771 first when both DTCs B1771 and B1795 are present.

DTC Code	DTC Detection Condition	Trouble Area
B1795	Occupant classification ECU malfunction	Occupant classification ECU

HINT:

When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1795 of the occupant classification system.
Use the Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

CAUTION / NOTICE / HINT

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work (See page ).
When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected (See page ).

PROCEDURE

1.	CHECK FOR DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Clear any DTCs stored in the memory (see page ).

HINT:

First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Using the Techstream, check for DTCs of the occupant classification ECU (see page ).

OK:

DTC B1795 is not output.

HINT:

DTCs other than DTC B1795 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

2.	REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

for Manual Seat (see page ).
for Power Seat (see page ).

HINT:

Perform the inspection using parts from a normal vehicle when possible.

3.	PERFORM ZERO POINT CALIBRATION

(a) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

(b) Connect the Techstream to the DLC3.

(d) Using the Techstream, perform the zero point calibration (see page ).

4.	PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check (see page ).

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

END

Open in Occupant Classification ECU Battery Positive Line (B1794)

Sleep Operation Failure of Occupant Classification ECU (B1796)

See More:

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