Toyota Sienna Service Manual: Occupant Classification ECU Malfunction

Toyota Sienna Service Manual / Supplemental restraint system / Occupant classification system / Diagnostic trouble code chart / 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

Turn the ignition switch to the ON position, and wait for at least 10 seconds.
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

Measure the resistance of the ECU-B fuse.

Resistance: Below 1 Ω

3 CHECK WIRE HARNESS (SOURCE VOLTAGE)

CHECK WIRE HARNESS (SOURCE VOLTAGE)

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

Standard voltage

Standard voltage

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

Standard resistance

Standard resistance

4 REPLACE OCCUPANT CLASSIFICATION ECU

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

5 PERFORM ZERO POINT CALIBRATION

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

OK: "COMPLETED" is displayed.

6 PERFORM SENSITIVITY CHECK

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

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

END

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Sleep Operation Failure of Occupant Classification ECU

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Other materials:

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Installation
1. INSTALL OCCUPANT CLASSIFICATION ECU Check that the ignition switch is off. Check that the negative battery (-) terminal is disconnected. CAUTION: After disconnecting the negative battery terminal, wait for at least 90 seconds before starting the operation. &nbs ...