B1783

SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1783: Rear Occupant Classification Sensor RH Circuit Malfunction
B1783 - Rear Occupant Classification Sensor RH Circuit Malfunction

DESCRIPTION

The rear occupant classification sensor RH circuit consists of the occupant detection ECU and rear occupant classification sensor RH.

DTC B1783 is stored when a malfunction is detected in the rear occupant classification sensor RH circuit.

HINT
When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant detection ECU. When DTC B1783 is output, perform troubleshooting for the DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Service Precautions.

HINT
* If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to see under the seat cushion.
* In the above case, lift and hold the seat so that it does not fall down. Hold the seat only as necessary because holding the seat for a long period of time may cause seat rail deformation.

PROCEDURE

1. CHECK CONNECTORS

(a) Turn the power switch off.

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

(c) Check that the connectors are properly connected to the occupant detection ECU and rear occupant classification sensor RH.

OK:

The connectors are properly connected.

HINT
If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

(d) Disconnect the connectors from the occupant detection ECU and rear occupant classification sensor RH.

(e) Check that the terminals of the connectors are not damaged.

OK:

The terminals are not deformed or damaged.

NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.

2. CHECK FRONT SEAT WIRE RH (SHORT TO B+)

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

(b) Turn the power switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

(d) Turn the power switch off.

(e) Disconnect the cable from the negative (-) auxiliary battery terminal.

Text in Illustration

NG -- REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH
OK -- Continue to next step.

3. CHECK FRONT SEAT WIRE RH (OPEN)

(a) Using a service wire, connect terminals 1 (SVC4) and 3 (SGD4), and connect terminals 2 (SIG4) and 3 (SGD4) of connector C.

NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

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

Standard Resistance:

NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.

4. CHECK FRONT SEAT WIRE RH (SHORT)

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

Standard Resistance:

Text in Illustration

NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.

5. CHECK FRONT SEAT WIRE RH (SHORT TO GROUND)

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

Standard Resistance:

Text in Illustration

NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.

6. CHECK DTC

(a) Connect the connectors to the occupant detection ECU and rear occupant classification sensor RH.

(b) Connect the cable to the negative (-) auxiliary battery terminal.

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

(d) Clear the DTCs stored in the airbag sensor assembly Separate Type Yaw Rate Sensor for Separate Type Yaw Rate Sensor, Built-in Type Yaw Rate Sensor for Built-in Type Yaw Rate Sensor).

(e) Turn the power switch off.

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

(g) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1783 is not output.

HINT
Codes other than DTC B1783 may be output at this time, but they are not related to this check.

(h) Turn the power switch off.

NG -- CHECK OCCUPANT DETECTION ECU

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

7. CHECK OCCUPANT DETECTION ECU

(a) Disconnect the cable from the negative (-) auxiliary battery terminal.

(b) Replace the occupant detection ECU with a known good one Removal.

HINT
Perform the following inspection using known good parts from another vehicle if possible.

(c) Connect the cable to the negative (-) auxiliary battery terminal.

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

(e) Clear the DTCs stored in the airbag sensor assembly Separate Type Yaw Rate Sensor for Separate Type Yaw Rate Sensor, Built-in Type Yaw Rate Sensor for Built-in Type Yaw Rate Sensor).

(f) Turn the power switch off.

(g) Turn the power switch on (IG).

(h) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1783 is not output.

HINT
Codes other than DTC B1783 may be output at this time, but they are not related to this check.

(i) Turn the power switch off.

(j) Disconnect the cable from the negative (-) auxiliary battery terminal.

(k) Restore the occupant detection ECU that was installed for testing to its original location Removal.

NG -- REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH
OK -- Continue to next step.

8. REPLACE OCCUPANT DETECTION ECU

(a) Disconnect the cable from the negative (-) auxiliary battery terminal.

(b) Replace the occupant detection ECU with a new one Removal.

(c) Connect the cable to the negative (-) auxiliary battery terminal.

NEXT -- Continue to next step.

9. PERFORM ZERO POINT CALIBRATION AND SENSITIVITY CHECK

(a) Using the Techstream, perform Zero Point Calibration and Sensitivity Check Programming and Relearning.

NEXT -- END

10. REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH

(a) Disconnect the cable from the negative (-) auxiliary battery terminal.

(b) Replace the front seat frame with adjuster assembly RH Removal for Manual Seat, Removal for Power Seat).

(c) Connect the cable to the negative (-) auxiliary battery terminal.

NEXT -- Continue to next step.

11. PERFORM ZERO POINT CALIBRATION AND SENSITIVITY CHECK

(a) Using the Techstream, perform Zero Point Calibration and Sensitivity Check Programming and Relearning.

NEXT -- END

12. REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH

(a) Disconnect the cable from the negative (-) auxiliary battery terminal.

(b) Replace the front seat frame with adjuster assembly RH Removal for Manual Seat, Removal for Power Seat).

NOTICE:
Replace the front seat wire RH at the same time.

HINT
When the front seat wire RH has a short to B+, the rear occupant classification sensor RH will be damaged. Therefore, replace the front seat wire RH and the front seat frame with adjuster assembly RH, which includes the rear occupant classification sensor RH.

(c) Connect the cable to the negative (-) auxiliary battery terminal.

NEXT -- Continue to next step.

13. PERFORM ZERO POINT CALIBRATION AND SENSITIVITY CHECK

(a) Using the Techstream, perform Zero Point Calibration and Sensitivity Check Programming and Relearning.

NEXT -- END