B1653

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

DTC B1653/35 - Seat Position Airbag Sensor Circuit Malfunction

DESCRIPTION

The seat position sensor circuit consists of the center airbag sensor assembly and the seat position sensor.
DTC B1653/35 is set when a malfunction is detected in the seat position sensor assembly circuit.

*1: Bench seat
*2: Separate seat

WIRING DIAGRAM

INSPECTION PROCEDURE

CAUTION: In order to prevent unexpected airbag deployment, disconnect the following connectors before inspecting parts such as wire harnesses, if the application of tester probes to the center airbag sensor assembly connector is necessary.

(a) Turn the ignition switch to the LOCK position.

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

(c) Disconnect the connectors from the center airbag sensor assembly.

(d) Disconnect the connectors from the steering pad.

(e) Disconnect the connector from the front passenger airbag assembly.

(f) Disconnect the connector from the front seat outer belt assembly LH.

(g) Disconnect the connector from the front seat outer belt assembly RH.

HINT: Skip the following steps if side and curtain shield airbags are not fitted.

(h) Disconnect the connector from the front seat airbag assembly LH.

(i) Disconnect the connector from the front seat airbag assembly RH.

(j) Disconnect the connector from the curtain shield airbag assembly LH.

(k) Disconnect the connector from the curtain shield airbag assembly RH.

PROCEDURE

1. CHECK DTC

(a) Turn the ignition switch to the ON position.
(b) Clear any DTCs stored in the memory (Reading and Clearing Diagnostic Trouble Codes).
(c) Turn the ignition switch to the LOCK position.
(d) Turn the ignition switch to the ON position and wait for at least 60 seconds.
(e) Check for DTCs (Reading and Clearing Diagnostic Trouble Codes).
OK:
DTC B1653/35 is not output.

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

OK -- USE SIMULATION METHOD TO CHECK
NG -- Continue to next step.
2. CHECK CONNECTION OF CONNECTORS
(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Check that the connectors are properly connected to the center airbag sensor assembly and the seat position sensor.
OK:
The connectors are properly connected.
NG -- CONNECT CONNECTORS
OK -- Continue to next step.
3. CHECK CONNECTORS
(a) Check that the connectors (on the center airbag sensor assembly side and seat position sensor side) are not damaged (Electronic Circuit Inspection Procedure).
OK:
The connectors are not deformed or damaged.

C -- REPAIR OR REPLACE WIRE HARNESS
B -- CHECK SEAT POSITION SENSOR CIRCUIT (FOR OPEN)
A -- Continue to next step.
4. CHECK SEAT POSITION SENSOR CIRCUIT (FOR OPEN)

(a) Disconnect the connectors from the center airbag sensor assembly and the seat position sensor.
(b) Using a service wire, connect 1 and 2 of connector E.

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

HINT: The connector is not allocated an ID number due to being part of the front seat inner belt assembly LH wire harness.

(c) Measure the resistance.
Standard resistance:

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (FOR OPEN)
OK -- Continue to next step.
5. CHECK SEAT POSITION SENSOR CIRCUIT (FOR SHORT)

(a) Disconnect the service wire from connector E.
(b) Measure the resistance.
Standard resistance:

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (FOR SHORT)
OK -- Continue to next step.
6. CHECK SEAT POSITION SENSOR CIRCUIT (TO B+)

(a) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage.
Standard voltage:

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (TO B+)
OK -- Continue to next step.
7. CHECK SEAT POSITION SENSOR CIRCUIT (TO GROUND)

(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Measure the resistance.
Standard resistance:

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (TO GROUND)
OK -- Continue to next step.
8. CHECK SEAT POSITION SENSOR

(a) Connect the connectors to the center airbag sensor assembly.
(b) Connect the connector to the seat position sensor.
(c) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(d) Turn the ignition switch to the ON position, and wait for at least 60 seconds.
(e) Clear any DTCs stored in the memory (Reading and Clearing Diagnostic Trouble Codes).
(f) Turn the ignition switch to the LOCK position.
(g) Turn the ignition switch to the ON position, 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: DTCs other than B1653/35 may be output at this time, but they are not related to this check.

NG -- REPLACE SEAT POSITION SENSOR
OK -- USE SIMULATION METHOD TO CHECK
9. CHECK SEAT POSITION SENSOR CIRCUIT (FOR OPEN)

(a) Disconnect the front seat inner belt assembly connector from the instrument panel wire.

HINT:
- The service wire has already been inserted into connector E.
- The connector is not allocated an ID number due to being part of the front seat inner belt assembly LH wire harness.

(b) Measure the resistance.
Standard resistance:

NG -- REPAIR OR REPLACE FRONT SEAT INNER BELT ASSEMBLY LH
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
10. CHECK SEAT POSITION SENSOR CIRCUIT (FOR SHORT)

(a) Disconnect the front seat inner belt assembly connector from the instrument panel wire.

HINT: The connector is not allocated an ID number due to being part of the front seat inner belt assembly LH wire harness.

(b) Disconnect the service wire from connector E.
(c) Measure the resistance.
Standard resistance:

NG -- REPAIR OR REPLACE FRONT SEAT INNER BELT ASSEMBLY LH
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
11. CHECK SEAT POSITION SENSOR CIRCUIT (TO B+)

(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Disconnect the seat inner belt assembly LH connector from the instrument panel wire.

HINT: The connector is not allocated an ID number due to being part of the front seat inner belt assembly LH wire harness.

(d) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(e) Turn the ignition switch to the ON position.
(f) Measure the voltage.
Standard Voltage:

NG -- REPAIR OR REPLACE FRONT SEAT INNER BELT ASSEMBLY LH
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
12. CHECK SEAT POSITION SENSOR CIRCUIT (TO GROUND)

NG -- REPAIR OR REPLACE FRONT SEAT INNER BELT ASSEMBLY LH
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
13. CHECK SEAT POSITION SENSOR CIRCUIT (FOR OPEN)

(a) Disconnect the connectors from the center airbag sensor assembly and the seat position sensor.
(b) Using a service wire, connect S25-1 and S25-2 of connector G.

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

(c) Measure the resistance.
Standard resistance:

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (FOR OPEN)
OK -- Continue to next step.
14. CHECK SEAT POSITION SENSOR CIRCUIT (FOR SHORT)

(a) Disconnect the service wire from connector G.
(b) Measure the resistance.
Standard resistance:

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (FOR SHORT)
OK -- Continue to next step.
15. CHECK SEAT POSITION SENSOR CIRCUIT (TO B+)

(a) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage.
Standard voltage:

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (TO B+)
OK -- Continue to next step.
16. CHECK SEAT POSITION SENSOR CIRCUIT (TO GROUND)

NG -- CHECK SEAT POSITION SENSOR CIRCUIT (TO GROUND)
OK -- Continue to next step.
17. CHECK SEAT POSITION SENSOR

(a) Disconnect the No. 2 seat wire connector from the No. 2 floor wire.

HINT: The service wire has already been inserted into connector G.

(b) Measure the resistance.
Standard resistance:

NG -- CHECK NO.1 SEAT WIRE (FOR OPEN)
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
19. CHECK SEAT POSITION SENSOR CIRCUIT (FOR SHORT)

(a) Disconnect the No. 2 seat wire connector from the No. 2 floor wire.
(b) Measure the resistance.
Standard resistance:

NG -- CHECK NO.1 SEAT WIRE (FOR SHORT)
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
20. CHECK SEAT POSITION SENSOR CIRCUIT (TO B+)

(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Disconnect the No. 2 seat wire connector from the No. 2 floor wire.
(d) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(e) Turn the ignition switch to the ON position.
(f) Measure the voltage.
Standard Voltage:

NG -- CHECK NO.1 SEAT WIRE (TO B+)
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
21. CHECK SEAT POSITION SENSOR CIRCUIT (TO GROUND)

(a) Disconnect the No. 2 seat wire connector from the No. 2 floor wire.
(b) Measure the resistance.
Standard resistance:

NG -- CHECK NO.1 SEAT WIRE (TO GROUND)
OK -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
22. CHECK NO.1 SEAT WIRE (FOR OPEN)

(a) Disconnect the No. 1 seat wire connector from the No. 2 seat wire.

HINT: The service wire has already been inserted into connector G.

(b) Measure the resistance.
Standard resistance:

NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- REPAIR OR REPLACE NO. 2 SEAT WIRE
23. CHECK NO.1 SEAT WIRE (FOR SHORT)

(a) Disconnect the No. 1 seat wire connector from the No. 2 seat wire.
(b) Measure the resistance.
Standard resistance:

NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- REPAIR OR REPLACE NO. 2 SEAT WIRE
24. CHECK NO.1 SEAT WIRE (TO B+)

(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Disconnect the No. 1 seat wire connector from the No. 2 seat wire.
(d) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(e) Turn the ignition switch to the ON position.
(f) Measure the voltage.
Standard Voltage:

NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- REPAIR OR REPLACE NO. 2 SEAT WIRE
25. CHECK NO.1 SEAT WIRE (TO GROUND)

(a) Disconnect the No. 1 seat wire connector from the No. 2 seat wire.
(b) Measure the resistance.
Standard resistance:

NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- REPAIR OR REPLACE NO. 2 SEAT WIRE
26. REPLACE SEAT POSITION SENSOR
(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Replace the seat position sensor.

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

NEXT -- Continue to next step.
27. CHECK CENTER AIRBAG SENSOR ASSEMBLY

(a) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(b) Turn the ignition switch to the ON position, and wait for at least 60 seconds.
(c) Clear any DTCs stored in the memory (Reading and Clearing Diagnostic Trouble Codes).
(d) Turn the ignition switch to the LOCK position.
(e) Turn the ignition switch to the ON position, and wait for at least 60 seconds.
(f) Check for DTCs (Reading and Clearing Diagnostic Trouble Codes).
OK:
DTC B1653/35 is not output.

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

NG -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
OK -- END