Occupant Classification System (from 12/2010)

SUPPLEMENTAL RESTRAINT SYSTEM: OCCUPANT CLASSIFICATION SYSTEM: B1794: Open in Occupant Classification ECU Battery Positive Line
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 off-on (IG)-off 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 input.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK BATTERY

(a) Measure the voltage of the battery.

Voltage:

11 to 14 V

NG -- REPLACE BATTERY
OK -- Continue to next step.

2. CHECK FUSE

(a) Check the ECU-B fuse.

Resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

3. CHECK WIRE HARNESS (SOURCE VOLTAGE)

(a) Turn the ignition switch off.





(b) Disconnect the negative (-) terminal cable from the battery.

(c) Disconnect the connector from the occupant classification ECU.

(d) Connect the negative (-) terminal cable to the battery.

(e) Turn the ignition switch on (IG).

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

Standard voltage and resistance:





NG -- REPAIR OR REPLACE WIRE HARNESS
OK -- Continue to next step.

4. CHECK DTC

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery.

(c) Connect the connector to the occupant classification ECU.

(d) Connect the Techstream to the DLC3.

(e) Connect the negative (-) terminal cable to the battery.

(f) Turn the ignition switch on (IG).

(g) Clear the DTCs stored in the occupant classification ECU Reading and Clearing Diagnostic Trouble Codes.

(h) Clear the DTCs stored in the center airbag sensor assembly DTC Check / Clear (from 12/2010).

(i) Turn the ignition switch off.

(j) Turn the ignition switch on (IG), and wait for at least 10 seconds.

(k) Using the Techstream, check the DTCs of the occupant classification ECU Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1794 is not output.

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

NG -- REPLACE OCCUPANT CLASSIFICATION ECU

OK -- USE SIMULATION METHOD TO CHECK

5. REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery.

(c) Replace the occupant classification ECU Removal (from 12/2010).

NEXT -- Continue to next step.

6. PERFORM ZERO POINT CALIBRATION

(a) Connect the negative (-) terminal cable to the battery.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch on (IG).

(d) Using the Techstream, perform the "Zero point calibration" Programming and Relearning.

OK:

The "Zero Point Calibration is complete." is displayed.

NEXT -- Continue to next step.

7. PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the "Sensitivity check" Programming and Relearning.

Standard value:

27 to 33 kg (59.52 to 72.75 lb)

NEXT -- END