AIRBAG SYSTEM, Diagnostic DTC:B161A/8A

DTC Code DTC Name
B161A/8A Lost Communication with Front Satellite Sensor Bus

DESCRIPTION

The front collision sensor circuit (front airbag sensor RH circuit and front airbag sensor LH circuit) is composed of the airbag ECU assembly, front airbag sensor RH and front airbag sensor LH.

The front airbag sensor RH and front airbag sensor LH detect impacts to the vehicle and send signals to the airbag ECU assembly to determine if the airbags and pretensioners should be deployed.

DTC B161A/8A is stored when a malfunction is detected in the front collision sensor circuit (front airbag sensor RH circuit and front airbag sensor LH circuit).

DTC No. Detection Item DTC Detection Condition Trouble Area Test Mode / Check Mode
B161A/8A Lost Communication with Front Satellite Sensor Bus

Any of the following conditions is met:


  • The airbag ECU assembly detects a line short, short to ground or B+, or an open in the front collision sensor circuit (front airbag sensor RH circuit and front airbag sensor LH circuit).

  • Front airbag sensor RH malfunction

  • Front airbag sensor LH malfunction

  • Airbag ECU assembly malfunction

  • Instrument panel wire

  • Engine room main wire

  • Front airbag sensor RH

  • Front airbag sensor LH

  • Airbag ECU assembly

 Does not apply to test/check mode
DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3 Pattern 4
Diagnosis Condition - - - - -
Malfunction Status The airbag ECU assembly detects a line short, short to ground or B+, or an open in the front collision sensor circuit (front airbag sensor RH circuit and front airbag sensor LH circuit) ○ - - -
Front airbag sensor RH malfunction - ○ - -
Front airbag sensor LH malfunction - - ○ -
Airbag ECU assembly malfunction - - - ○
Detection Time - - - -
Number of Trips 1 trip 1 trip 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

B002DJ9E17
*a Front Airbag Sensor RH
*b Front Airbag Sensor LH
*c Airbag ECU Assembly

PROCEDURE


  1. CHECK DTC


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

    2. Turn the engine switch off.

      Tech Tips

      If a communication error occurs, DTCs for both the LH and RH sides will be stored simultaneously. To identify the malfunctioning area, turn the engine switch off and then on (IG) again.

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

    4. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes

      Tech Tips


      • DTCs indicating communication errors will be changed to DTCs indicating errors in initialization by turning the engine switch off and then on (IG) again.

      • Codes other than DTCs B1613/83 and B1618/84 may be output at this time, but they are not related to this check.

      Result
      Result Proceed to
      DTCs B1613/83 and B1618/84 are not output. A
      DTC B1613/83 is output. B
      DTC B1618/84 is output. C

    B

    GO TO DTC B1613/83 Click here

    C

    GO TO DTC B1618/84 Click here

    A

  2. CHECK DTC


    1. Clear the DTCs stored in memory.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    2. Turn the engine switch off.

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

    4. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      OK
      DTC B161A/8A is not output.

      Tech Tips

      Codes other than DTC B161A/8A may be output at this time, but they are not related to this check.

      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIRBAG ECU ASSEMBLY Click here