AIRBAG SYSTEM, Diagnostic DTC:B1651

DTC Code	DTC Name
B1651	Airbag ON-OFF Switch

DESCRIPTION

The passenger airbag cut-off switch circuit consists of the center airbag sensor assembly and the airbag cut off switch.

DTC B1651 is set when a malfunction is detected in the airbag cut-off switch circuit.

DTC No.	DTC Detecting Conditions	Trouble Areas
B1651	Center airbag sensor assembly receives line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in airbag cut off switch circuit for 2 seconds Airbag cut-off switch malfunction Center airbag sensor assembly malfunction	Instrument panel wire Airbag cut-off switch Center airbag sensor assembly

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.

Turn the ignition switch to the LOCK position.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Disconnect the connectors from the center airbag sensor assembly.
Disconnect the connectors from the steering pad.
Disconnect the connector from the front passenger airbag assembly.
Disconnect the connector from the front seat outer belt assembly LH.
Disconnect the connector from the front seat outer belt assembly RH.

Tech Tips

Skip the following steps if side and curtain shield airbags are not fitted.
Disconnect the connector from the front seat airbag assembly LH.
Disconnect the connector from the front seat airbag assembly RH.
Disconnect the connector from the curtain shield airbag assembly LH.
Disconnect the connector from the curtain shield airbag assembly RH.

PROCEDURE

CHECK DTC
1. Turn the ignition switch to the ON position.
2. Clear any DTCs stored in the memory.
3. Turn the ignition switch to the LOCK position.
4. Turn the ignition switch to the ON position and wait for at least 60 seconds.
5. Check for DTCs.
  
  OK
  
  DTC B1651 is not output.
  
  Tech Tips
  
  DTCs other than B1651 may be output at this time, but they are not related to this check.
NG
CHECK CONNECTION OF CONNECTOR Click here

OK

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

OK
CHECK CONNECTOR
1. Check that the connectors (on the center airbag sensor assembly side and airbag cut-off switch side) are not damaged Click here.
  
  OK
  
  The connectors are not deformed or damaged.
NG
REPAIR OR REPLACE WIRE HARNESS AND CONNECTORS

OK

OK
DTC B1651 is not output.

OK
The connectors are properly connected.

OK
The connectors are not deformed or damaged.

INSPECT AIRBAG CUT-OFF SWITCH

Disconnect the C29 airbag cut-off switch connector.

Measure the resistance.

Standard Resistance

Switch Condition

Tester Connection

Specified Condition

OFF

6 (MSW+) -

3 (MSW-)

90 to 110 Ω

6 (MSW+) -

3 (MSW-)

360 to 440 Ω

REPLACE AIRBAG CUT-OFF SWITCH

CHECK INSTRUMENT PANEL WIRE (FOR OPEN)

Disconnect the instrument panel wire connector from the airbag cut-off switch.
Using a service wire, connect C29-6 (MSW+) and C29-3 (MSW-) of connector C.

Note

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

Measure the resistance.

Standard Resistance

Tester Connection

Condition

Specified Condition

C19-9 (MSW+) -

C19-8 (MSW-)

Always

Below 1 Ω

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

CHECK INSTRUMENT PANEL WIRE (FOR SHORT)

Disconnect the service wire from connector C.

Measure the resistance.

Standard Resistance

Tester Connection

Condition

Specified Condition

C19-9 (MSW+) -

C19-8 (MSW-)

Always

1 MΩ or Higher

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

CHECK INSTRUMENT PANEL WIRE (TO B+)

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

Measure the voltage.

Standard Voltage

Tester Connection

Condition

Specified Condition

C19-9 (MSW+) -

Body ground

Ignition switch ON

Below 1 V

C19-8 (MSW-) -

Body ground

Ignition switch ON

Below 1 V

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

CHECK INSTRUMENT PANEL WIRE (TO GROUND)

Turn the ignition switch to the LOCK position.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

Measure the resistance.

Standard Resistance

Tester Connection

Condition

Specified Condition

C19-9 (MSW+) -

Body ground

Always

1 MΩ or Higher

C19-8 (MSW-) -

Body ground

Always

1 MΩ or Higher

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

CHECK CENTER AIRBAG SENSOR ASSEMBLY
1. Connect the connectors to the center airbag sensor assembly and airbag cut-off switch.
2. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
3. Turn the ignition switch to the ON position, and wait for at least 60 seconds.
4. Clear any DTCs stored in the memory.
5. Turn the ignition switch to the LOCK position.
6. Turn the ignition switch to the ON position, and wait for at least 60 seconds.
7. Check for DTCs.
  
  OK
  
  DTC B1651 is not output.
  
  Tech Tips
  
  DTCs other than B1651 may be output at this time, but they are not related to this check.
NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY

OK

USE SIMULATION METHOD TO CHECK