AIRBAG SYSTEM, Diagnostic DTC:B1653/35

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

DESCRIPTION

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

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

for LHD
DTC Code	Detection Condition	Trouble Area
B1653/35	One of the following conditions is met: The center airbag sensor assembly 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 airbag sensor circuit for 2 seconds. Seat position airbag sensor malfunction Center airbag sensor assembly malfunction	No. 2 floor wire Seat position airbag sensor (front seat inner belt LH) Center airbag sensor assembly

for RHD
DTC Code	Detection Condition	Trouble Area
B1653/35	One of the following conditions is met: The center airbag sensor assembly 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 airbag sensor circuit for 2 seconds. Seat position airbag sensor malfunction Center airbag sensor assembly malfunction	Floor wire Seat position airbag sensor (front seat inner belt RH) Center airbag sensor assembly

WIRING DIAGRAM

INSPECTION PROCEDURE

Note

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 Click here.
When disconnecting the cable from the negative (-) auxiliary 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 RHD	A
for LHD	B

CHECK FOR DTC Click here

CHECK FOR DTC
1. Turn the power switch ON (IG), and wait for at least 60 seconds.
2. Clear the DTCs Click here.
3. Turn the power switch OFF.
4. Turn the power 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 power switch OFF.
2. Disconnect the negative (-) terminal cable from the auxiliary battery, and wait for at least 90 seconds.
3. Check that the connectors are properly connected to the center airbag sensor assembly and the seat position airbag sensor.
  
  OK
  
  The connectors are properly connected.
NG
CONNECT CONNECTORS PROPERLY

OK
CHECK CONNECTORS
1. Disconnect the connectors from the center airbag sensor assembly and the seat position airbag sensor.
2. Check that the connectors (on the center airbag sensor assembly side and seat position airbag 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
The connectors are properly connected.

OK
The connectors are not deformed or damaged.

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

Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.
Turn the power switch ON (IG).

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

Standard voltage

Tester Connection	Switch Condition	Specified Condition
S17-2 (LSP+) - Body ground	Power switch ON (IG)	Below 1 V
S17-4 (LSP-) - Body ground	Power switch ON (IG)	Below 1 V

Turn the power switch OFF.
Disconnect the negative (-) terminal cable from the auxiliary battery, and wait for at least 90 seconds.

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

Standard resistance

Tester Connection	Condition	Specified Condition
S17-2 (LSP+) - S8-9 (LSP+)	Always	Below 1 Ω

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

Standard resistance

Tester Connection	Condition	Specified Condition
S17-2 (LSP+) - Body ground	Always	1 MΩ or higher
S17-4 (LSP-) - Body ground	Always	Below 1 Ω

REPLACE NO. 2 FLOOR WIRE

CHECK SEAT POSITION AIRBAG SENSOR (FRONT SEAT INNER BELT LH)
1. Connect the connectors to the center airbag sensor assembly and the seat position airbag sensor.
2. Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.
3. Turn the power switch ON (IG), and wait for at least 60 seconds.
4. Clear the DTCs stored in the memory Click here.
5. Turn the power switch OFF.
6. Turn the power 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 AIRBAG SENSOR (FRONT SEAT INNER BELT LH) Click here

OK

USE SIMULATION METHOD TO CHECK Click here
REPLACE SEAT POSITION AIRBAG SENSOR (FRONT SEAT INNER BELT LH)
1. Turn the power switch OFF.
2. Disconnect the negative (-) terminal cable from the auxiliary battery, and wait for at least 90 seconds.
3. Replace the front seat inner belt LH Click here.
  
  Tech Tips
  
  Perform the inspection using parts from a normally functioning vehicle if possible.
NEXT
CHECK CENTER AIRBAG SENSOR ASSEMBLY
1. Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.
2. Turn the power switch ON (IG), and wait for at least 60 seconds.
3. Clear the DTCs Click here.
4. Turn the power switch OFF.
5. Turn the power 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 INNER BELT ASSEMBLY LH Click here
CHECK FOR DTC
1. Turn the power switch ON (IG), and wait for at least 60 seconds.
2. Clear the DTCs Click here.
3. Turn the power switch OFF.
4. Turn the power 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 CONNECTORS Click here

OK

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

OK
CHECK CONNECTION OF CONNECTORS
1. Disconnect the connectors from the center airbag sensor assembly and the seat position airbag sensor.
2. Check that the connectors (on the center airbag sensor assembly side and seat position airbag 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
DTC B1653 is not output.

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 ASSEMBLY - SEAT POSITION AIRBAG SENSOR)

Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.
Turn the power switch ON (IG).

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

Standard voltage

Tester Connection	Switch Condition	Specified Condition
R49-2 (RSP+) - Body ground	Power switch ON (IG)	Below 1 V
R49-4 (RSP-) - Body ground	Power switch ON (IG)	Below 1 V

Turn the power switch OFF.
Disconnect the negative (-) terminal cable from the auxiliary battery, and wait for at least 90 seconds.

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

Standard resistance

Tester Connection	Condition	Specified Condition
R49-2 (RSP+) - S8-9 (LSP+)	Always	Below 1 Ω

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

Standard resistance

Tester Connection	Condition	Specified Condition
R49-2 (RSP+) - Body ground	Always	1 MΩ or higher
R49-4 (RSP-) - Body ground	Always	Below 1 Ω

REPLACE FLOOR WIRE

CHECK SEAT POSITION AIRBAG SENSOR (FRONT SEAT INNER BELT RH)
1. Connect the connectors to the center airbag sensor assembly and the seat position airbag sensor.
2. Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.
3. Turn the power switch ON (IG), and wait for at least 60 seconds.
4. Clear the DTCs stored Click here.
5. Turn the power switch OFF.
6. Turn the power 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
INSPECT SEAT POSITION AIRBAG SENSOR (FRONT SEAT INNER BELT RH) Click here

OK

USE SIMULATION METHOD TO CHECK Click here
INSPECT SEAT POSITION AIRBAG SENSOR (FRONT SEAT INNER BELT RH)
1. Turn the power switch OFF.
2. Disconnect the negative (-) terminal cable from the auxiliary battery, and wait for at least 90 seconds.
3. Replace the front seat inner belt RH Click here.
  
  Tech Tips
  
  Perform the inspection using parts from a normally functioning vehicle if possible.
NEXT
CHECK CENTER AIRBAG SENSOR ASSEMBLY
1. Connect the negative (-) terminal cable to the auxiliary battery, and wait for at least 2 seconds.
2. Turn the power switch ON (IG), and wait for at least 60 seconds.
3. Clear the DTCs Click here.
4. Turn the power switch OFF.
5. Turn the power 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 INNER BELT ASSEMBLY RH Click here