AIRBAG SYSTEM, Diagnostic DTC:B1653/35

DTC Code	DTC Name
B1653/35	Seat Position Airbag Sensor Circuit Malfunction

DESCRIPTION

The seat position sensor circuit consists of the center airbag sensor and the seat position sensor.

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

for LHD
DTC Code	DTC Detection Condition	Trouble Area
B1653/35	When one of the following conditions is met: The center airbag sensor receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the seat position sensor circuit for 2 seconds. A seat position sensor malfunction. A center airbag sensor malfunction.	Floor wire Seat position sensor Center airbag sensor assembly

for RHD
DTC Code	DTC Detection Condition	Trouble Area
B1653/35	When one of the following conditions is met: The center airbag sensor receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the seat position sensor circuit for 2 seconds. A seat position sensor malfunction. A center airbag sensor malfunction.	No. 2 floor wire Seat position sensor Center airbag sensor assembly

WIRING DIAGRAM

INSPECTION PROCEDURE

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 Click here.
When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected Click here.

PROCEDURE

CHECK VEHICLE CONDITION

Check vehicle condition.

Result
Result	Proceed to
for LHD	A
for RHD	B

CHECK FOR DTC Click here

CHECK FOR DTC
1. Turn the engine switch on (IG).
2. Clear the DTCs Click here.
3. Turn the engine switch off.
4. Turn the engine switch on (IG), and wait for at least 60 seconds.
5. Check for DTCs Click here.
  
  OK
  
  DTC B1653 is not output.
  
  Tech Tips
  
  Codes other than DTC B1653 may be output at this time, but they are not related to this check.
NG
CHECK CONNECTION OF CONNECTORS Click here

OK

USE SIMULATION METHOD TO CHECK Click here
CHECK CONNECTION OF CONNECTORS
1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Check that the connectors are properly connected to the center airbag sensor and the seat position sensor.
  
  OK
  
  The connectors are properly connected.
NG
CONNECT CONNECTORS PROPERLY

OK
CHECK CONNECTORS
1. Disconnect the connectors from the center airbag sensor and the seat position sensor.
2. Check that the connectors (on the center airbag sensor side and seat position sensor side) are not damaged.
  
  OK
  
  The connectors are not deformed or damaged.
NG
REPLACE FLOOR WIRE

OK

OK
DTC B1653 is not output.

OK
The connectors are properly connected.

OK
The connectors are not deformed or damaged.

CHECK FLOOR WIRE (CENTER AIRBAG SENSOR - SEAT POSITION SENSOR)

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

Tester Connection	Switch Condition	Specified Condition
K10-4 (LSP+) - Body ground	Engine switch on (IG)	Below 1 V
K10-8 (LSP-) - Body ground	Engine switch on (IG)	Below 1 V

Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Using a service wire, connector terminals 9 (LSP+) and 17 (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

Tester Connection	Condition	Specified Condition
K10-4 (LSP+) - K10-8 (LSP-)	Always	Below 1 Ω

Disconnect a service wire from connector B.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
K10-4 (LSP+) - K10-8 (LSP-)	Always	1 MΩ or higher
K10-4 (LSP+) - Body ground	Always	1 MΩ or higher
K10-8 (LSP-) - Body ground	Always	1 MΩ or higher

REPLACE FLOOR WIRE

CHECK SEAT POSITION SENSOR
1. Connect the connectors to the center airbag sensor and the seat position sensor.
2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
3. Turn the engine switch on (IG), and wait for at least 60 seconds.
4. Clear the DTCs stored in the memory Click here.
5. Turn the engine switch off.
6. Turn the engine switch on (IG), and wait for at least 60 seconds.
7. Check for DTCs Click here.
  
  OK
  
  DTC B1653 is not output.
  
  Tech Tips
  
  Codes other than DTC B1653 may be output at this time, but they are not related to this check.
NG
REPLACE SEAT POSITION SENSOR Click here

OK

USE SIMULATION METHOD TO CHECK Click here
REPLACE SEAT POSITION SENSOR
1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Replace the seat position sensor Click here.
  
  Tech Tips
  
  Perform the inspection using parts from a normally functioning vehicle if possible.
NEXT
CHECK CENTER AIRBAG SENSOR
1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
2. Turn the engine switch on (IG), and wait for at least 60 seconds.
3. Clear the DTCs Click here.
4. Turn the engine switch off.
5. Turn the engine switch on (IG), and wait for at least 60 seconds.
6. Check for DTCs Click here.
  
  OK
  
  DTC B1653 is not output.
  
  Tech Tips
  
  Codes other than DTC B1653 may be output at this time, but they are not related to this check.
NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

OK

REPLACE SEAT POSITION SENSOR Click here
CHECK FOR DTC
1. Turn the engine switch on (IG), and wait for at least 60 seconds.
2. Clear the DTCs Click here.
3. Turn the engine switch off.
4. Turn the engine switch on (IG), and wait for at least 60 seconds.
5. Check for DTCs Click here.
  
  OK
  
  DTC B1653/35 is not output.
  
  Tech Tips
  
  Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.
NG
CHECK CONNECTION OF CONNECTORS Click here

OK

USE SIMULATION METHOD TO CHECK Click here
CHECK CONNECTION OF CONNECTORS
1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Check that the connectors are properly connected to the center airbag sensor and the seat position sensor.
  
  OK
  
  The connectors are properly connected.
NG
CONNECT CONNECTORS PROPERLY

OK
CHECK CONNECTORS
1. Disconnect the connectors from the center airbag sensor and the seat position sensor.
2. Check that the connectors (on the center airbag sensor side and seat position sensor side) are not damaged.
  
  OK
  
  The connectors are not deformed or damaged.
NG
REPLACE NO. 2 FLOOR WIRE

OK

OK
DTC B1653 is not output.

OK
DTC B1653 is not output.

OK
DTC B1653/35 is not output.

OK
The connectors are properly connected.

OK
The connectors are not deformed or damaged.

CHECK NO. 2 FLOOR WIRE (CENTER AIRBAG SENSOR - SEAT POSITION SENSOR)

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 the value(s) in the table below.

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
L48-4 (RSP+) - Body ground	Engine switch on (IG)	Below 1 V
L48-8 (RSP-) - Body ground	Engine switch on (IG)	Below 1 V

Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Using a service wire, connector terminals 16 (RSP+) and 24 (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

Tester Connection	Condition	Specified Condition
L48-4 (RSP+) - L48-8 (RSP-)	Always	Below 1 Ω

Disconnect a service wire from connector B.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
L48-4 (RSP+) - L48-8 (RSP-)	Always	1 MΩ or higher
L48-4 (RSP+) - Body ground	Always	1 MΩ or higher
L48-8 (RSP-) - Body ground	Always	1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

CHECK SEAT POSITION SENSOR
1. Connect the connectors to the center airbag sensor and the seat position sensor.
2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
3. Turn the engine switch on (IG), and wait for at least 60 seconds.
4. Clear the DTCs stored Click here.
5. Turn the engine switch off.
6. Turn the engine switch on (IG), and wait for at least 60 seconds.
7. Check for DTCs Click here.
  
  OK
  
  DTC B1653/35 is not output.
  
  Tech Tips
  
  Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.
NG
REPLACE SEAT POSITION SENSOR Click here

OK

USE SIMULATION METHOD TO CHECK Click here
REPLACE SEAT POSITION SENSOR
1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Replace the seat position sensor Click here.
  
  Tech Tips
  
  Perform inspection using parts from a normal vehicle if possible.
NEXT
CHECK CENTER AIRBAG SENSOR
1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
2. Turn the engine switch on (IG), and wait for at least 60 seconds.
3. Clear the DTCs Click here.
4. Turn the engine switch off.
5. Turn the engine switch on (IG), and wait for at least 60 seconds.
6. Check for DTCs Click here.
  
  OK
  
  DTC B1653/35 is not output.
  
  Tech Tips
  
  Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.
NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

OK

REPLACE SEAT POSITION SENSOR Click here