Supplemental Restraint System. Dtc B1650/32 Occupant Detection Sensor Circuit Malfunction

The occupant detection sensor circuit consists of the center airbag sensor assembly and the occupant detection sensor.
If the center airbag sensor assembly receives signals from the occupant detection sensor, it determines whether or not the front passenger airbag assembly and the front passenger side-side airbag should be operated.
DTC B1650/32 is recorded when a malfunction is detected in the occupant detection sensor circuit.

DTC No.	DTC Detecting Condition	Trouble Area
B1650/32	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 occupant detection sensor circuit for 2 seconds. Occupant detection sensor malfunction Center airbag sensor assembly malfunction	Floor wire (LHD) Floor wire No.2 (RHD) Occupant detection sensor Center airbag sensor assembly

WIRING DIAGRAM

Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System.
Dtc
B1650/32 Occupant Detection Sensor Circuit Malfunction

INSPECTION PROCEDURE

1.CHECK DTC

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

Clear the DTCs stored in memory (Click here).

Turn the engine switch off.

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

Check the DTCs (Click here).
OK:
DTC B1650/32 is not output.
HINT:
Codes other than DTC B1650/32 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

NG

2.CHECK CONNECTION OF CONNECTORS

Turn the engine switch off.

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

Check that the connectors are properly connected to the center airbag sensor assembly and the occupant detection sensor.
OK:
The connectors are connected.

CONNECT CONNECTORS, THEN GO TO STEP 1

OK

3.CHECK VEHICLE STEERING POSITION

Confirm that the vehicle steering position.

Result:

Result
Proceed to
LHD
A
RHD
B

Go to step 8

A

4.CHECK FLOOR WIRE (OPEN)

Disconnect the connectors from the center airbag sensor assembly and the occupant detection sensor.

Using a service wire, connect V13-9 (FSR+) and V13-17 (FSR-) of connector "B".
NOTICE:
Do not forcibly insert a service wire into the terminals of the connector when connecting.

Measure the resistance according to the value(s) in the table below.
Resistance:
Tester connection
Condition
Specified condition
V39-2 (FSR+) -
V39-4 (FSR-)
Always
Below 1 Ω

REPAIR OR REPLACE FLOOR WIRE

OK

Go to step 4

5.CHECK FLOOR WIRE (SHORT)

Disconnect the service wire from connector "B".

Measure the resistance according to the value(s) in the table below.
Resistance:
Tester connection
Condition
Specified condition
V39-2 (FSR+) -
V39-4 (FSR-)
Always
1 MΩ or higher

REPAIR OR REPLACE FLOOR WIRE

OK

Go to step 5

6.CHECK FLOOR WIRE (SHORT TO B+)

Connect the negative (-) terminal cable to the battery, 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.
Voltage:
Tester connection
Condition
Specified condition
V39-2 (FSR+) -
Body ground
Engine switch on (IG)
Below 1 V
V39-4 (FSR-) -
Body ground
Engine switch on (IG)
Below 1 V

REPAIR OR REPLACE FLOOR WIRE

OK

Go to step 6

7.CHECK FLOOR WIRE (SHORT TO GROUND)

Turn the engine switch off.

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

Measure the resistance according to the value(s) in the table below.
Resistance:
Tester connection
Condition
Specified condition
V39-2 (FSR+) -
Body ground
Always
1 MΩ or higher
V39-4 (FSR-) -
Body ground
Always
1 MΩ or higher

REPAIR OR REPLACE FLOOR WIRE

GO TO STEP 12

8.CHECK FLOOR WIRE NO.2 (OPEN)

Disconnect the connectors from the center airbag sensor assembly and the occupant detection sensor.

Using a service wire, connect W16-16 (FSL+) and W16-24 (FSL-) of connector "B".
NOTICE:
Do not forcibly insert a service wire into the terminals of the connector when connecting.

Measure the resistance according to the value(s) in the table below.
Resistance:
Tester connection
Condition
Specified condition
W4-2 (FSL+) -
W4-4 (FSL-)
Always
Below 1 Ω

REPAIR OR REPLACE FLOOR WIRE NO.2

OK

9.CHECK FLOOR WIRE NO.2 (SHORT)

Disconnect the service wire from connector "B".

Measure the resistance according to the value(s) in the table below.
Resistance:
Tester connection
Condition
Specified condition
W4-2 (FSL+) -
W4-4 (FSL-)
Always
1 MΩ or higher

REPAIR OR REPLACE FLOOR WIRE NO.2

OK

10.CHECK FLOOR WIRE NO.2 (SHORT TO B+)

Connect the negative (-) terminal cable to the battery, 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.
Voltage:
Tester connection
Condition
Specified condition
W4-2 (FSL+) -
Body ground
Engine switch on (IG)
Below 1 V
W4-4 (FSL-) -
Body ground
Engine switch on (IG)
Below 1 V

REPAIR OR REPLACE FLOOR WIRE NO.2

OK

11.CHECK FLOOR WIRE NO.2 (SHORT TO GROUND)

Turn the engine switch off.

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

Measure the resistance according to the value(s) in the table below.
Resistance:
Tester connection
Condition
Specified condition
W4-2 (FSL+) -
Body ground
Always
1 MΩ or higher
W4-4 (FSL-) -
Body ground
Always
1 MΩ or higher

REPAIR OR REPLACE FLOOR WIRE NO.2

OK

12.CHECK OCCUPANT DETECTION SENSOR

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

NOTICE:

Connect the positive tester lead to terminal FSR+ (FSL+), and the negative tester lead to terminal FSR- (FSL-).

Resistance:

Tester connection	Condition	Specified condition
V39-2 (FSR+) - V39-4 (FSR-) (*1)	Passenger is not seated	Below 50 kΩ
V39-2 (FSR+) - V39-4 (FSR-) (*1)	Passenger is seated	50 kΩ or higher
W4-2 (FSL+) - W4-4 (FSL-) (*2)	Passenger is not seated	Below 50 kΩ
W4-2 (FSL+) - W4-4 (FSL-) (*2)	Passenger is seated	50 kΩ or higher

*1: LHD
*2: RHD

REPLACE OCCUPANT DETECTION SENSOR

OK

13.CHECK CENTER AIRBAG SENSOR ASSEMBLY

Connect the connectors to the center airbag sensor assembly and the occupant detection sensor.

Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

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

Clear the DTCs stored in memory (Click here).

Turn the engine switch off.

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

Check the DTCs (Click here).
OK:
DTC B1650/32 is not output.
HINT:
Codes other than DTC B1650/32 may be output at this time, but they are not related to this check.

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

USE SIMULATION METHOD TO CHECK

Result	Proceed to
LHD	A
RHD	B