Lost Communication with Front Airbag Sensor LH - Airbag System

SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1617/84, B1618/84: Lost Communication with Front Airbag Sensor LH
B1618/84 - Front Airbag Sensor LH Initialization Incomplete

DESCRIPTION

The front airbag sensor LH circuit consists of the center airbag sensor assembly and front airbag sensor LH.

The front airbag sensor LH detects impacts to the vehicle and sends signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1617/84 or B1618/84 is recorded when a malfunction is detected in the front airbag sensor LH circuit.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC

(a) Turn the ignition switch off.

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

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

OK:

DTC B161A/8A is not output.

NG -- GO TO DTC B161A/8A B161A
OK -- Continue to next step.

2. CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition switch off.

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

(c) Check that the connectors are properly connected to the center airbag sensor assembly and the front airbag sensor LH.

OK:

The connectors are properly connected.

NG -- CONNECT CONNECTORS PROPERLY
OK -- Continue to next step.

3. CHECK CONNECTORS

(a) Disconnect the connectors from the center airbag sensor assembly and front airbag sensor LH.

(b) Check that the connectors (on the center airbag sensor assembly side and front airbag sensor LH side) are not damaged.

OK:

The connectors are not deformed or damaged.

NG -- REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

4. CHECK FRONT AIRBAG SENSOR LH CIRCUIT





Text in Illustration





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

(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, and wait for at least 90 seconds.

(f) Using a service wire, connect terminals 30 and 28 of connector B.

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

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

Standard Resistance:





(h) Disconnect the service wire from connector B.

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

Standard Resistance:





NG -- CHECK INSTRUMENT PANEL WIRE (CENTER AIRBAG SENSOR ASSEMBLY - ENGINE ROOM MAIN WIRE)
OK -- Continue to next step.

5. CHECK FRONT AIRBAG SENSOR LH





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

(b) Interchange the front airbag sensor LH with RH and connect the connectors to them.

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

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

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

(f) Turn the ignition switch off.

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

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

Result





Text in Illustration





HINT
DTCs other than B1612, B1613, B1617, B1618, 83 and 84 may be output at this time, but they are not related to this check.

(i) Turn the ignition switch off.

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

(k) Return the front airbag sensor LH and front airbag sensor RH to their original positions and connect the connectors to them.

A -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY Removal

B -- REPLACE FRONT AIRBAG SENSOR LH Removal

C -- USE SIMULATION METHOD TO CHECK Diagnosis System

6. CHECK INSTRUMENT PANEL WIRE (CENTER AIRBAG SENSOR ASSEMBLY - ENGINE ROOM MAIN WIRE)





Text in Illustration





(a) Disconnect the instrument panel wire connector from the engine room main wire.

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

(c) Turn the ignition switch to ON.

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

Standard Voltage:





(e) Turn the ignition switch off.

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

(g) Using a service wire, connect terminals 30 and 28 of connector B.

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

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

Standard Resistance:





(i) Disconnect the service wire from connector B.

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

Standard Resistance:





NG -- REPLACE INSTRUMENT PANEL WIRE

OK -- REPLACE ENGINE ROOM MAIN WIRE