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Home >> Subaru >> 2017 >> WRX Base >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Air Bag System (Diagnostics) >> Diagnostic Chart with Trouble Code >> DTC B1618 Front Sub Sensor LH Initialization Error

DTC B1618 Front Sub Sensor LH Initialization Error

DIAGNOSIS START CONDITION: 

Ignition voltage is 10 V to 16 V.

DTC DETECTING CONDITION: 

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". <Ref. to CAUTION , General Description.>

WIRING DIAGRAM: 

Airbag system <Ref. to WIRING DIAGRAM , Airbag System.>

Fig 1: Front Sub Sensor LH Initialization Error Wiring Diagram
G09484066Courtesy of SUBARU OF AMERICA, INC.
Step Check Yes No
1 CHECK POOR CONTACT OF CONNECTORS. 
Check for poor contact of the connectors (AB6, AB13) between the airbag control module and the front sub sensor LH.
Is there poor contact? Replace the airbag main harness along with body harness. Go to step 2  .
2 CHECK AIRBAG MAIN HARNESS (FRONT SENSOR BUS LH). 
  1. Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more.
  2. Remove the instrument panel lower cover and column cover, and disconnect the connectors (AB7) and (AB2).
  3. Remove the console front panel and disconnect the connector (AB9).
  4. Disconnect the connector (AB66) from knee airbag module.
  5. Disconnect the connectors (AB6, AB17, AB18) from airbag control module.
  6. Connect the connector (1 AG) in the test harness AG to the connectors (AB6, AB17, AB18).
  7. Disconnect the connector (AB13) from the front sub sensor LH, and then connect the connector (1H) in the test harness H to connector (AB13).
  8. Measure the resistance between connector (4AG) in the test harness AG and connector (3H) in the test harness H.

Connector & terminal 
(4AG) No. 7 - (3H) No. 5: 
(4AG) No. 9 - (3H) No. 6: 
Is the resistance less than 10 Ω? Go to step 3  . Replace the airbag main harness along with body harness.
3 CHECK AIRBAG MAIN HARNESS (FRONT SENSOR BUS LH). 
Measure the resistance between connector (4AG) in the test harness AG and chassis ground, and the resistance between connector (4AG) terminals in the test harness AG.
Connector & terminal 
(4AG) No. 7 - Chassis ground: 
(4AG) No. 9 - Chassis ground: 
(4AG) No. 7 - (4AG) No. 9: 
Is the resistance 1 MΩ or more? Go to step 4  . Replace the airbag main harness along with body harness.
4 CHECK AIRBAG CONTROL MODULE. 
  1. Connect all connectors.
  2. Clear the memory. <Ref. to CLEAR MEMORY MODE .>
  3. Perform the Inspection Mode. <Ref. to INSPECTION MODE .>
  4. Read the DTC. (Current malfunction) <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>
Is DTC B1618 displayed? Replace the front sub sensor LH. <Ref. to REMOVAL , Front Sub Sensor.> Replace the airbag control module if not operating normally even after replacing the sensor. <Ref. to REMOVAL , Airbag Control Module.> Go to step 5  .
5 CHECK FOR ANY OTHER DTC ON DISPLAY. 
Read the DTC. (Current malfunction) <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>
Is any other DTC displayed? Perform the diagnosis for other displayed DTCs. <Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .> Finish the diagnosis.