DESCRIPTION
The seat position airbag sensor circuit consists of the airbag ECU assembly and seat position airbag sensor.
DTC B1653/35 is stored when a malfunction is detected in the seat position airbag sensor circuit.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Test Mode / Check Mode |
|---|---|---|---|---|---|
| B1653/35 | Seat Position Airbag Sensor Circuit Malfunction | One of the following conditions is met:
|
|
Comes on | Not applicable |
WIRING DIAGRAM
Figure 1. for LHD:
| *a | VS |
| *b | Seat Position Airbag Sensor |
| *c | Front Seat Inner Belt Assembly LH |
| *d | Airbag ECU Assembly |
Figure 2. for RHD:
CAUTION / NOTICE / HINT
Note
After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.
PROCEDURE
CHECK VEHICLE CONDITION
Check vehicle condition.
| Result | |||
|---|---|---|---|
|
| for RHD |
|
CHECK CONNECTION OF CONNECTORS Click here |
| for LHD |
|
CHECK CONNECTION OF CONNECTORS
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Check that the connectors are properly connected to the airbag ECU assembly and seat position airbag sensor.
| Result | |||
|---|---|---|---|
|
| Connectors are not properly connected |
|
CONNECT CONNECTORS PROPERLY |
| Connectors are properly connected |
|
CHECK CONNECTORS
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
| *3 | Front Seat Inner Belt Assembly LH |
| *4 | Floor Wire |
Disconnect the connectors from the airbag ECU assembly and seat position airbag sensor.
Check that the connectors (on the airbag ECU assembly side and seat position airbag sensor side) are not damaged.
| Result | |||
|---|---|---|---|
|
| Connectors are deformed or damaged |
|
REPLACE FLOOR WIRE OR FRONT SEAT INNER BELT ASSEMBLY LH |
| Connectors are not deformed or damaged |
|
CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
| *3 | Front Seat Inner Belt Assembly LH |
| *4 | Floor Wire |
| *5 | Service Wire |
| *a | Front view of wire harness connector (to Seat Position Airbag Sensor) |
| *b | Front view of wire harness connector (to Airbag ECU Assembly) |
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Using a service wire, connect terminals 26 (LSP-) and 25 (LSP+) of connector B.
Note
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Disconnect the service wire from connector B.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK FLOOR WIRE Click here |
| OK |
|
CHECK DTC
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
Connect the connectors to the airbag ECU assembly and seat position airbag sensor.
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Clear the DTCs.
Turn the engine switch off.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Check for DTCs.
| Result | |||
|---|---|---|---|
|
Tech Tips
Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.
| DTC B1653/35 is not output |
|
USE SIMULATION METHOD TO CHECK Click here |
| DTC B1653/35 is output |
|
REPLACE SEAT POSITION AIRBAG SENSOR
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Replace the seat position airbag sensor.
Tech Tips
Perform the inspection using parts from a normal vehicle if possible.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK DTC
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Clear the DTCs.
Turn the engine switch off.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Check for DTCs.
| Result | |||
|---|---|---|---|
|
Tech Tips
Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.
| DTC B1653/35 is not output |
|
END (SEAT POSITION AIRBAG SENSOR WAS DEFECTIVE) |
| DTC B1653/35 is output |
|
REPLACE AIRBAG ECU ASSEMBLY Click here |
CHECK FLOOR WIRE
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
| *3 | Front Seat Inner Belt Assembly LH |
| *4 | Floor Wire |
| *5 | Service Wire |
| *a | Front view of wire harness connector (to Front Seat Inner Belt Assembly LH) |
| *b | Front view of wire harness connector (to Airbag ECU Assembly) |
Disconnect the floor wire connector from the front seat inner belt assembly LH.
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Using a service wire, connect terminals 26 (LSP-) and 25 (LSP+) of connector B.
Note
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Disconnect the service wire from connector B.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here |
| NG |
|
REPLACE FLOOR WIRE |
CHECK CONNECTION OF CONNECTORS
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Check that the connectors are properly connected to the airbag ECU assembly and seat position airbag sensor.
| Result | |||
|---|---|---|---|
|
| Connectors are not properly connected |
|
CONNECT CONNECTORS PROPERLY |
| Connectors are properly connected |
|
CHECK CONNECTORS
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
| *3 | Front Seat Inner Belt Assembly RH |
| *4 | Floor Wire |
Disconnect the connectors from the airbag ECU assembly and seat position airbag sensor.
Check that the connectors (on the airbag ECU assembly side and seat position airbag sensor side) are not damaged.
| Result | |||
|---|---|---|---|
|
| Connectors are deformed or damaged |
|
REPLACE FLOOR WIRE OR FRONT SEAT INNER BELT ASSEMBLY RH |
| Connectors are not deformed or damaged |
|
CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
| *3 | Front Seat Inner Belt Assembly RH |
| *4 | Floor Wire |
| *5 | Service Wire |
| *a | Front view of wire harness connector (to Seat Position Airbag Sensor) |
| *b | Front view of wire harness connector (to Airbag ECU Assembly) |
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Using a service wire, connect terminals 31 (RSP-) and 32 (RSP+) of connector B.
Note
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Disconnect the service wire from connector B.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK FLOOR WIRE Click here |
| OK |
|
CHECK DTC
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
Connect the connectors to the airbag ECU assembly and seat position airbag sensor.
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Clear the DTCs.
Turn the engine switch off.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Check for DTCs.
| Result | |||
|---|---|---|---|
|
Tech Tips
Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.
| DTC B1653/35 is not output |
|
USE SIMULATION METHOD TO CHECK Click here |
| DTC B1653/35 is output |
|
REPLACE SEAT POSITION AIRBAG SENSOR
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Replace the seat position airbag sensor.
Tech Tips
Perform the inspection using parts from a normal vehicle if possible.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK DTC
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Clear the DTCs.
Turn the engine switch off.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Check for DTCs.
| Result | |||
|---|---|---|---|
|
Tech Tips
Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.
| DTC B1653/35 is not output |
|
END (SEAT POSITION AIRBAG SENSOR WAS DEFECTIVE) |
| DTC B1653/35 is output |
|
REPLACE AIRBAG ECU ASSEMBLY Click here |
CHECK FLOOR WIRE
| *1 | Seat Position Airbag Sensor |
| *2 | Airbag ECU Assembly |
| *3 | Front Seat Inner Belt Assembly RH |
| *4 | Floor Wire |
| *5 | Service Wire |
| *a | Front view of wire harness connector (to Front Seat Inner Belt Assembly RH) |
| *b | Front view of wire harness connector (to Airbag ECU Assembly) |
Disconnect the floor wire connector from the front seat inner belt assembly RH.
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Using a service wire, connect terminals 31 (RSP-) and 32 (RSP+) of connector B.
Note
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Disconnect the service wire from connector B.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE FRONT SEAT INNER BELT ASSEMBLY RH Click here |
| NG |
|
REPLACE FLOOR WIRE |