Part 1

SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1627, B1628, B1637, B1638, B1647, B1697, B1698; Side Airbag Sensor LH Lost Communication; 2013 MY FR-S [03/2012 -]
B1627 - Side Airbag Sensor LH Lost Communication
B1628 - Side Airbag Sensor LH Initialization
B1637 - Side No. 2 Airbag Sensor LH Lost Communication
B1638 - Side No. 2 Airbag Sensor LH Initialization
B1647 - Side Satellite Sensor Bus Lost Communication (LH)
B1697 - Lost Communication with Side Airbag Sensor LH
B1698 - Side Airbag Sensor LH Initialization Incomplete

DESCRIPTION

The side collision sensor LH circuit (to determine deployment of the front seat airbag assembly LH, curtain shield airbag assembly LH and front seat outer belt assembly LH) is composed of the airbag ECU assembly, side airbag sensor assembly LH, side No. 2 airbag sensor assembly LH and rear airbag sensor LH and No. 2 airbag sensor assembly.

The side airbag sensor assembly LH, side No. 2 airbag sensor assembly LH and rear airbag sensor LH detect impacts to the vehicle and send signals to the airbag ECU assembly to determine if the airbag should be deployed.

These DTCs are stored when a malfunction is detected for the side collision sensor LH circuit.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
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 Service Precautions.

PROCEDURE

1. CHECK CURRENT DTC

(a) Check for current DTCs Reading and Clearing Diagnostic Trouble Codes.

Result:

HINT
* DTCs indicating communication errors will be changed to DTCs indicating errors in initialization by turning the ignition switch off and then to ON again.
* Codes other than current DTCs B1627, B1628, B1637, B1638, B1647, B1697 and B1698 may be output at this time, but they are not related to this check.

B -- CHECK HISTORY DTC

C -- CHECK CONNECTORS

D -- CHECK CURRENT DTC

E -- USE SIMULATION METHOD TO CHECK
A -- Continue to next step.

2. CHECK CONNECTORS

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(c) Check that the connectors are properly connected to the airbag ECU assembly, side airbag sensor assembly LH, side No. 2 airbag sensor assembly LH and rear airbag sensor LH. Also check that the connectors that link the floor wire and front door wire LH are properly connected.

OK:

The connectors are properly connected.

HINT
If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

(d) Disconnect the connectors from the airbag ECU assembly, side airbag sensor assembly LH, side No. 2 airbag sensor assembly LH and rear airbag sensor LH. Also disconnect the connectors that link the floor wire and front door wire LH.

(e) Check that the terminals of the connectors are not damaged.

OK:

The terminals are not deformed or damaged.

NG -- REPLACE WIRE HARNESS
OK -- Continue to next step.

3. CHECK FLOOR WIRE (OPEN)

(a) Using a service wire, connect terminals 8 (BBL+) and 15 (BBL-) of connector B.

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

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

Standard Resistance:

(c) Disconnect the service wire from connector B.

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

4. CHECK FLOOR WIRE (SHORT)

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

Standard Resistance:

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

5. CHECK FLOOR WIRE (SHORT TO B+)

(a) Connect the cable to the negative (-) battery terminal.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

(d) Turn the ignition switch off.

(e) Disconnect the cable from the negative (-) battery terminal.

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

6. CHECK FLOOR WIRE (SHORT TO GROUND)

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

Standard Resistance:

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

7. CHECK FLOOR WIRE (OPEN)

(a) Using a service wire, connect terminals 4 (BUSIN) and 3 (RTNIN) of connector C.

(c) Disconnect the service wire from connector C.

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

8. CHECK FLOOR WIRE (SHORT)

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

Standard Resistance:

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

9. CHECK FLOOR WIRE (SHORT TO B+)

(a) Connect the cable to the negative (-) battery terminal.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

(d) Turn the ignition switch off.

(e) Disconnect the cable from the negative (-) battery terminal.

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

10. CHECK FLOOR WIRE (SHORT TO GROUND)

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

Standard Resistance:

NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.

11. CHECK SIDE AIRBAG SENSOR ASSEMBLY LH CIRCUIT (OPEN)

(a) Connect the connectors that link the floor wire and front door wire LH.

(b) Using a service wire, connect terminals 2 (BUSIN) and 1 (RTNIN) of connector E.

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

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

Standard Resistance:

NG -- CHECK FRONT DOOR WIRE LH (OPEN)
OK -- Continue to next step.

12. CHECK SIDE AIRBAG SENSOR ASSEMBLY LH CIRCUIT (SHORT)

(a) Disconnect the service wire from connector E.

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

Standard Resistance:

NG -- CHECK FRONT DOOR WIRE LH (SHORT)
OK -- Continue to next step.