B1653

SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1653/35: Seat Position Airbag Sensor Circuit Malfunction
B1653/35 - Seat Position Airbag Sensor Circuit Malfunction

DESCRIPTION

The seat position airbag sensor circuit consists of the airbag ECU assembly, front seat inner belt assembly LH and seat position airbag sensor.

DTC B1653/35 is stored when a malfunction is detected in the seat position airbag sensor circuit.

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.

PROCEDURE

1. CHECK CONNECTORS

(a) Turn the power switch off.

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

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

(c) Check that the connectors are properly connected to the airbag ECU assembly, front seat inner belt assembly LH and seat position airbag sensor.

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 airbag ECU assembly, front seat inner belt assembly LH and seat position airbag sensor.

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

OK:

The terminals are not deformed or damaged.

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

2. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (OPEN)

(a) Connect the connectors to the front seat inner belt assembly LH and floor wire.

(b) Using a service wire, connect terminals 14 (LSP+) and 13 (LSP-) of connector B.

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

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

Standard Resistance:

Text in Illustration

NG -- CHECK FLOOR WIRE (OPEN)
OK -- Continue to next step.

3. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT)

(a) Disconnect the service wire from connector B.

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

Standard Resistance:

Text in Illustration

NG -- CHECK FLOOR WIRE (SHORT)
OK -- Continue to next step.

4. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (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.

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

Text in Illustration

NG -- CHECK FLOOR WIRE (SHORT TO B+)
OK -- Continue to next step.

5. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO GROUND)

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

Standard Resistance:

Text in Illustration

NG -- CHECK FLOOR WIRE (SHORT TO GROUND)
OK -- Continue to next step.

6. CHECK DTC

(a) Connect the connectors to the airbag ECU assembly and seat position airbag sensor.

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

(c) Turn the power switch on (IG), and wait for at least 60 seconds.

(d) Clear the DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the power switch off.

(f) Turn the power switch on (IG), and wait for at least 60 seconds.

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

OK:

DTC B1653/35 is not output.

HINT
Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.

(h) Turn the power switch off.

Text in Illustration

NG -- CHECK SEAT POSITION AIRBAG SENSOR

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

7. CHECK SEAT POSITION AIRBAG SENSOR

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

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

(b) Replace the seat position airbag sensor 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) Turn the power switch on (IG), and wait for at least 60 seconds.

(e) Clear the DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.

(f) Turn the power switch off.

(g) Turn the power switch on (IG), and wait for at least 60 seconds.

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

OK:

DTC B1653/35 is not output.

HINT
Codes other than DTC B1653/35 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 seat position airbag sensor that was installed for testing to its original location Removal.

Text in Illustration

NG -- REPLACE AIRBAG ECU ASSEMBLY Removal

OK -- REPLACE SEAT POSITION AIRBAG SENSOR Removal

8. CHECK FLOOR WIRE (OPEN)

(a) Disconnect the floor wire from the front seat inner belt assembly LH.

HINT
The service wire has already been inserted into connector B.

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

Standard Resistance:

NG -- REPLACE FLOOR WIRE

OK -- REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Removal

9. CHECK FLOOR WIRE (SHORT)

(a) Disconnect the floor wire from the front seat belt inner belt assembly LH.

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

Standard Resistance:

Text in Illustration

NG -- REPLACE FLOOR WIRE

OK -- REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Removal

10. CHECK FLOOR WIRE (SHORT TO B+)

(a) Disconnect the floor wire from the front seat inner belt assembly LH.

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

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

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

Standard Voltage:

Text in Illustration

NG -- REPLACE FLOOR WIRE

OK -- REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Removal

11. CHECK FLOOR WIRE (SHORT TO GROUND)

(a) Disconnect the floor wire from the front seat inner belt assembly LH.

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

Standard Resistance:

Text in Illustration

NG -- REPLACE FLOOR WIRE

OK -- REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Removal