B1821

SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: B1820/55-B1823/55: Short in Front Driver Side - Side Squib Circuit


DESCRIPTION

The side squib (driver seat side) circuit consists of the center airbag sensor assembly and the front seat with adjuster frame assembly LH.

This circuit signals the SRS to deploy when airbag deployment conditions are met.

These DTCs are set when a malfunction is detected in the side squib (driver seat side) circuit.





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.

* (a) Turn the ignition switch to the LOCK position.

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

* (c) Disconnect the connectors from the center airbag sensor assembly.

* (d) Disconnect the connectors from the steering pad.

* (e) Disconnect the connector from the front passenger airbag assembly.

* (f) Disconnect the connector from the front seat airbag assembly LH.

* (g) Disconnect the connector from the front seat airbag assembly RH.

HINT
Skip the following steps if side and curtain shield airbags are not fitted.

* (h) Disconnect the connector from the curtain shield airbag assembly LH.

* (i) Disconnect the connector from the curtain shield airbag assembly RH.

* (j) Disconnect the connector from the front seat outer belt assembly LH.

* (k) Disconnect the connector from the front seat outer belt assembly RH.

PROCEDURE

1. CHECK DTC

(a) Proceed to the appropriate step according to DTC readings.

(1) If using the Techstream (read the 5-digit DTCs):

Using the Techstream, check for DTCs DTC Check / Clear.

Result:





(2) If not using the Techstream (read the 2-digit DTCs): Check for DTCs DTC Check / Clear.

Result:





E -- CHECK NO. 2 FLOOR WIRE (SIDE SQUIB (DRIVER SEAT SIDE) CIRCUIT)

D -- CHECK NO. 2 FLOOR WIRE (TO B+)

C -- CHECK NO. 2 FLOOR WIRE (TO GROUND)

B -- CHECK NO. 2 FLOOR WIRE (FOR OPEN)
A -- Continue to next step.

2. CHECK NO. 2 FLOOR WIRE (FOR SHORT)

(a) Release the activation prevention mechanism built into connector B Diagnosis System.





(b) Measure the resistance.

Standard resistance:





OK -- CHECK CENTER AIRBAG SENSOR ASSEMBLY

NG -- REPAIR OR REPLACE NO. 2 FLOOR WIRE

3. CHECK NO. 2 FLOOR WIRE (FOR OPEN)

(a) Measure the resistance.

Standard resistance:









OK -- CHECK CENTER AIRBAG SENSOR ASSEMBLY

NG -- REPAIR OR REPLACE NO. 2 FLOOR WIRE

4. CHECK NO. 2 FLOOR WIRE (TO GROUND)

(a) Measure the resistance.

Standard resistance:









OK -- CHECK CENTER AIRBAG SENSOR ASSEMBLY

NG -- REPAIR OR REPLACE NO. 2 FLOOR WIRE

5. CHECK NO. 2 FLOOR WIRE (TO B+)

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





(b) Turn the ignition switch to the ON position.

(c) Measure the voltage.

Standard voltage:





OK -- CHECK CENTER AIRBAG SENSOR ASSEMBLY

NG -- REPAIR OR REPLACE NO. 2 FLOOR WIRE

6. CHECK NO. 2 FLOOR WIRE (SIDE SQUIB (DRIVER SEAT SIDE) CIRCUIT)

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





(b) Turn the ignition switch to the ON position.

(c) Measure the voltage.

Standard voltage:





(d) Turn the ignition switch to the LOCK position.

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

(f) Measure the resistance.

Standard resistance:





(g) Release the activation prevention mechanism built into connector B Diagnosis System.

(h) Measure the resistance.

Standard resistance:





NG -- REPAIR OR REPLACE NO. 2 FLOOR WIRE
OK -- Continue to next step.

7. REPLACE FRONT SEAT WITH ADJUSTER FRAME ASSEMBLY LH (SIDE SQUIB (DRIVER SEAT SIDE))

(a) Replace the front seat with adjuster frame assembly LH Removal.





HINT
Perform the inspection using parts from a normal vehicle when possible.

(b) Connect the connectors to the center airbag sensor assembly.

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

(d) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(e) Clear any DTCs stored in the memory DTC Check / Clear.

(f) Turn the ignition switch to the LOCK position.

(g) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(h) Check for DTCs DTC Check / Clear.

OK:

DTC 55 is not output.

HINT
DTCs other than 55 may be output at this time, but they are not related to this check.

NG -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY

OK -- END

8. CHECK CENTER AIRBAG SENSOR ASSEMBLY

(a) Connect the connectors to the center airbag sensor assembly.





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

(c) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(d) Clear any DTCs stored in the memory DTC Check / Clear.

(e) Turn the ignition switch to the LOCK position.

(f) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(g) Check for DTCs DTC Check / Clear.

OK:

DTC B1820 is not output.

HINT
DTCs other than B1820 may be output at this time, but they are not related to this check.

OK -- CHECK FRONT SEAT WITH ADJUSTER FRAME ASSEMBLY LH

NG -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY

9. CHECK CENTER AIRBAG SENSOR ASSEMBLY

HINT
If continuing from step 5, begin from (a). If continuing from any other step, begin from (c).

(a) Turn the ignition switch to the LOCK position.





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

(c) Connect the connectors to the center airbag sensor assembly.

(d) Using a service wire, connect S26-1 (SFD+) and S26-2 (SFD-) of connector C.

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

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

(f) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(g) Clear any DTCs stored in the memory DTC Check / Clear.

(h) Turn the ignition switch to the LOCK position.

(i) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(j) Check for DTCs DTC Check / Clear.

OK:

DTC B1821, B1822 and B1823 are not output.

HINT
DTCs other than B1821, B1822 or B1823 may be output at this time, but they are not related to this check.

NG -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
OK -- Continue to next step.

10. CHECK FRONT SEAT WITH ADJUSTER FRAME ASSEMBLY LH





HINT
If continuing from step 9, begin from (c). If continuing from any other step, being from (a).

(a) Turn the ignition switch to the LOCK position.

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

(c) Disconnect the service wire from connector C.

(d) Connect the connector to the front seat with adjuster frame assembly LH.

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

(f) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(g) Clear any DTCs stored in the memory DTC Check / Clear.

(h) Turn the ignition switch to the LOCK position.

(i) Turn the ignition switch to the ON position, and wait for at least 60 seconds.

(j) Check for DTCs DTC Check / Clear.

OK:

DTC B1820, B1821, B1822 and B1823 are not output.

HINT
DTCs other than B1820, B1821, B1822 or B1823 may be output at this time, but they are not related to this check.

NG -- REPLACE FRONT SEAT WITH ADJUSTER FRAME ASSEMBLY LH

OK -- USE SIMULATION METHOD TO CHECK