B1656

SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1656/38: Seat Belt Buckle Switch LH Circuit Malfunction
B1656/38 - Seat Belt Buckle Switch LH Circuit Malfunction

DESCRIPTION

The seat belt buckle switch LH circuit consists of the airbag ECU assembly and front seat inner belt assembly LH.

DTC B1656/38 is stored when a malfunction is detected in the seat belt buckle switch LH circuit.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Service Precautions.

PROCEDURE

1. CHECK CONNECTORS

(a) Turn the power switch off.

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

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

(c) Check that the connectors are properly connected to the airbag ECU assembly and front seat inner belt assembly LH.

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 and front seat inner belt assembly LH.

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

OK:

The terminals are not deformed or damaged.

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

2. CHECK FLOOR WIRE (OPEN)

(a) Using a service wire, connect terminals 11 (LBE+) and 12 (LBE-) 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:

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

3. CHECK FLOOR WIRE (SHORT)

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

Standard Resistance:

Text in Illustration

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

4. CHECK FLOOR WIRE (SHORT TO B+)

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

(b) Turn the power switch on (IG).

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

Standard Voltage:

(d) Turn the power switch off.

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

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

Text in Illustration

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

5. CHECK FLOOR WIRE (SHORT TO GROUND)

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

Standard Resistance:

Text in Illustration

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

6. CHECK DTC

(a) Connect the connectors to the airbag ECU assembly and front seat inner belt assembly LH.

(b) Connect the cable to the negative (-) auxiliary battery terminal.

(c) Clear the DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.

(d) Turn the power switch off.

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

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

OK:

DTC B1656/38 is not output.

HINT
Codes other than DTC B1656/38 may be output at this time, but they are not related to this check.

Text in Illustration

NG -- CHECK FRONT SEAT INNER BELT ASSEMBLY LH

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

7. CHECK FRONT SEAT INNER BELT ASSEMBLY LH

(a) Turn the power switch off.

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

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

(c) Replace the front seat inner belt assembly LH with a known good one Removal.

HINT
Perform the following inspection using known good parts from another vehicle if possible.

(d) Connect the cable to the negative (-) auxiliary battery terminal.

(e) Clear the DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.

(f) Turn the power switch off.

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

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

OK:

DTC B1656/38 is not output.

HINT
Codes other than DTC B1656/38 may be output at this time, but they are not related to this check.

(i) Turn the power switch off.

(j) Disconnect the cable from the negative (-) auxiliary battery terminal.

(k) Restore the front seat inner belt assembly LH that was installed for testing to its original location Removal.

Text in Illustration

NG -- REPLACE AIRBAG ECU ASSEMBLY Removal

OK -- REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Removal