AIRBAG SYSTEM(w/ Occupant Classification System), Diagnostic DTC:B1800/51,B1801/51,B1802/51 and B1803/51

DTC Code	DTC Name
B1800/51	Short in Driver Side Squib Circuit
B1801/51	Open in Driver Side Squib Circuit
B1802/51	Short to GND in Driver Side Squib Circuit
B1803/51	Short to B+ in Driver Side Squib Circuit

DESCRIPTION

The driver side squib circuit consists of the airbag sensor assembly, spiral with sensor cable sub-assembly and horn button assembly.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the driver side squib circuit.


DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B1800/51	Short in Driver Side Squib Circuit	One of the following conditions is met: The airbag sensor assembly detects a line short circuit signal 5 times in the driver side squib circuit during the primary check. A driver side squib malfunction. A spiral with sensor cable sub-assembly malfunction. An airbag sensor assembly malfunction.	Instrument panel wire Spiral with sensor cable sub-assembly Horn button assembly (Driver side squib) Airbag sensor assembly
B1801/51	Open in Driver Side Squib Circuit	One of the following conditions is met: The airbag sensor assembly detects an open circuit signal in the driver side squib circuit for 2 seconds. A driver side squib malfunction. A spiral with sensor cable sub-assembly malfunction. An airbag sensor assembly malfunction.	Instrument panel wire Spiral with sensor cable sub-assembly Horn button assembly (Driver side squib) Airbag sensor assembly
B1802/51	Short to GND in Driver Side Squib Circuit	One of the following conditions is met: The airbag sensor assembly detects a short circuit to ground signal in the driver side squib circuit for 0.5 seconds. A driver side squib malfunction. A spiral with sensor cable sub-assembly malfunction. An airbag sensor assembly malfunction.	Instrument panel wire Spiral with sensor cable sub-assembly Horn button assembly (Driver side squib) Airbag sensor assembly
B1803/51	Short to B+ in Driver Side Squib Circuit	One of the following conditions is met: The airbag sensor assembly detects a short circuit to B+ signal in the driver side squib circuit for 0.5 seconds. A driver side squib malfunction. A spiral with sensor cable sub-assembly malfunction. An airbag sensor assembly malfunction.	Instrument panel wire Spiral with sensor cable sub-assembly Horn button assembly (Driver side squib) Airbag sensor assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

Note:

When installing the spiral with sensor cable sub-assembly and steering wheel, be sure to adjust the spiral with sensor cable sub-assembly as it may break if the steering wheel is turned before adjusting the spiral with sensor cable sub-assembly.
Click here Click here Click here
After turning the ignition 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 Click here Click here Click here 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 Click here Click here Click here Click here Click here
After replacing the airbag sensor assembly, refer to initialization.
Click here Click here Click here Click here Click here Click here

Tip:

To perform the simulation method, enter check mode (signal check) with the GTS (Click here), and then wiggle each connector of the airbag system or drive the vehicle on various types of road (Click here).

PROCEDURE

CHECK HORN BUTTON ASSEMBLY (DRIVER SIDE SQUIB)

*1	Driver Side Squib
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag Sensor Assembly
*4	Connector E
*5	SST
*a	Front view of wire harness connector (to Driver Side Squib)
*b	Color: Orange

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Disconnect the connectors from the horn button assembly.
Connect the white wire side of SST (resistance: 2.1 Ω) to connector E (orange connector).

CAUTION:
Never connect the tester to the horn button assembly (driver side squib) for measurement, as this may lead to a serious injury due to airbag deployment.
Note:
- Do not forcibly insert SST into the terminals of the connector when connecting SST.
- Insert SST straight into the terminals of the connector.
Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the ignition switch to ON, and wait for at least 60 seconds.
Clear the DTCs.
Click here

Body Electrical > SRS Airbag > Clear DTCs
Turn the ignition switch off.
Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs.

Click here

Body Electrical > SRS Airbag > Trouble Codes

Result


Proceed to
DTC B1800/51, B1801/51, B1802/51 or B1803/51 is not output
DTC B1800/51, B1801/51, B1802/51 or B1803/51 is output

Tip:

Codes other than DTC B1800/51, B1801/51, B1802/51 and B1803/51 may be output at this time, but they are not related to this check.

Turn the ignition switch off.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Disconnect SST from connector E.

09843-18061

DTC B1800/51, B1801/51, B1802/51 or B1803/51 is not output

REPLACE HORN BUTTON ASSEMBLY

Click here

DTC B1800/51, B1801/51, B1802/51 or B1803/51 is output

CHECK CONNECTORS

Disconnect the connectors from the airbag sensor assembly.

*1	Driver Side Squib
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag Sensor Assembly

Check that the connectors (on the airbag sensor assembly side and horn button assembly side) are not damaged.

The lock button is not disengaged, and the claw of the lock is not deformed or damaged.

Result


Proceed to
OK
NG

REPLACE HARNESS AND CONNECTOR OR SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY

CHECK DRIVER SIDE SQUIB CIRCUIT

*1	Driver Side Squib
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag Sensor Assembly
*4	Connector E
*a	Front view of wire harness connector (to Driver Side Squib)
*b	Color: Orange

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

Turn the ignition switch to ON.

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

Standard Voltage


Tester Connection	Switch Condition	Specified Condition
z2-2 (D+) - Body ground	Ignition switch ON	Below 1 V
z2-1 (D-) - Body ground	Ignition switch ON	Below 1 V

Turn the ignition switch off.
Disconnect the cable from the negative (-) battery terminal, 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
z2-2 (D+) - z2-1 (D-)	Always	Below 1 Ω

Release the activation prevention mechanism built into connector B.
Click here

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

Standard Resistance


Tester Connection	Condition	Specified Condition
z2-2 (D+) - z2-1 (D-)	Always	1 MΩ or higher

Restore the released activation prevention mechanism of connector B to its original condition.

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

Standard Resistance


Tester Connection	Condition	Specified Condition
z2-2 (D+) - Body ground	Always	1 MΩ or higher
z2-1 (D-) - Body ground	Always	1 MΩ or higher

Result


Proceed to
OK
NG

CHECK INSTRUMENT PANEL WIREClick here

CHECK AIRBAG SENSOR ASSEMBLY

*1	Driver Side Squib
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag Sensor Assembly

Connect the connectors to the horn button assembly and airbag sensor assembly.

Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
Turn the ignition switch to ON, and wait for at least 60 seconds.
Clear the DTCs.
Click here

Body Electrical > SRS Airbag > Clear DTCs
Turn the ignition switch off.
Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs.

Click here

Body Electrical > SRS Airbag > Trouble Codes

Result


Proceed to
DTC B1800/51, B1801/51, B1802/51 or B1803/51 is not output
DTC B1800/51, B1801/51, B1802/51 or B1803/51 is output

Tip:

Codes other than DTC B1800/51, B1801/51, B1802/51 and B1803/51 may be output at this time, but they are not related to this check.

DTC B1800/51, B1801/51, B1802/51 or B1803/51 is not output

USE SIMULATION METHOD TO CHECK

Click here

DTC B1800/51, B1801/51, B1802/51 or B1803/51 is output

REPLACE AIRBAG SENSOR ASSEMBLY

Click here

CHECK INSTRUMENT PANEL WIRE

*1	Instrument Panel Wire
*2	Spiral with Sensor Cable Sub-assembly
*3	Airbag Sensor Assembly
*4	Connector C
*a	Rear view of wire harness connector (to Spiral with Sensor Cable Sub-assembly)

Disconnect the instrument panel wire connector from the spiral with sensor cable sub-assembly.

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

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

Standard Voltage


Tester Connection	Switch Condition	Specified Condition
G9-1 (D+) - Body ground	Ignition switch ON	Below 1 V
G9-2 (D-) - Body ground	Ignition switch ON	Below 1 V

Turn the ignition switch off.
Disconnect the cable from the negative (-) battery terminal, 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
G9-1 (D+) - G9-2 (D-)	Always	Below 1 Ω

Release the activation prevention mechanism built into connector B.
Click here

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

Standard Resistance


Tester Connection	Condition	Specified Condition
G9-1 (D+) - G9-2 (D-)	Always	1 MΩ or higher

Restore the released activation prevention mechanism of connector B to its original condition.

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

Standard Resistance


Tester Connection	Condition	Specified Condition
G9-1 (D+) - Body ground	Always	1 MΩ or higher
G9-2 (D-) - Body ground	Always	1 MΩ or higher

Result


Proceed to
OK
NG

REPLACE SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY

Click here

REPLACE INSTRUMENT PANEL WIRE