B0085 GM left front side impact sensor circuit fault

B0085 left front side impact sensor (GM SIR light)

B0085 in short

On Chevrolet and GMC vehicles from about 2010 on, B0085 is a fault in the left front side impact sensor circuit and it turns on the airbag light. Wiring in the driver door or a corroded connector is the usual finding. The vehicle drives, but airbags may not fire, so get it checked soon.

A side impact sensor tells the airbag module when the door area is being hit hard. The module checks the sensor and its wiring every time the vehicle starts, and B0085 is set when the left front sensor circuit reads open, shorted or out of range.

In the sources read, the fault was usually in the wiring and not the sensor. A 2013 Yukon XL had a badly corroded connector in the left kick panel and the code cleared after the connector and pins were replaced. Owners of 2010 and 2012 Silverados and a 2015 Traverse report the driver door harness breaking open where it flexes, and one found that replacing the sensor changed nothing.

The queue listed this code as generic, but the sourced meaning is for GM vehicles only. A GM bulletin on 2003-2006 trucks pairs B0085 with seat position sensor wiring, so do not assume the same meaning on older trucks. Because the fault takes part of the airbag system out of service, diagnosis belongs with a trained technician.

Pick your make

B0085 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. Open wire in the driver door harness

    Supported by vehicle data
    Why it ranks here
    Three owners of 2010-2015 Silverado and Traverse describe an open circuit in the driver door harness with B0085 set, and one shop found it internal to the harness.
    What would change this
    Rises if the light comes and goes when the driver door is opened or closed. Falls if a shop finds the door harness intact.

  2. Corroded connector in the left kick panel

    Supported by vehicle data
    Why it ranks here
    A 2013 Yukon XL tech tip found connector X500 in the left kick panel severely corroded with B0085 set, and replacing it fixed the code.
    What would change this
    Rises if the vehicle has had water leaks or a wet left footwell. Falls if the connector pins look clean.

  3. The left front side impact sensor itself

    Possible — needs testing
    Why it ranks here
    The sensor is the named component, but the 2010 Silverado owner replaced it with no change, and the other sources found wiring.
    What would change this
    Rises only after the harness and connectors have been tested good.

  4. Airbag sensing and diagnostic module

    Possible — needs testing
    Why it ranks here
    One owner's list of possible faults includes the module, but no source confirmed a module failure for this code.
    What would change this
    Rises only if the circuit and sensor test good and the code returns.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Have a shop with an SRS-capable scan tool read the airbag module, note every stored code and its sub-code (open, short, high or low), and whether it is current or history.

    Best left to a shopTool: SRS-capable scan tool

    Warning:Airbag and seat belt pretensioner circuits can deploy if probed or disconnected incorrectly. Only a trained technician following the service manual should test them.

    • IfB0085 is current and the sub-code points to open or high resistance

      It meansThe sensor circuit is open or poorly connected; a shop checks the driver door harness and connectors next.

      Go to step 2

    • IfThe code is history only and the light is off

      It meansThe fault may be intermittent, for example a wire that opens when the door moves. Tell the shop when it happens.

  2. Shop checks the driver door hinge-area harness and the left kick panel connector for breaks and corrosion before replacing the sensor.

    Best left to a shopTool: Service manual wiring diagram, multimeter

    Warning:The sensor circuit is part of the airbag system; the battery must be disconnected and the manual's wait time followed before any airbag connector is touched, or an airbag could deploy.

Symptoms

  • Airbag or Service SRS message and light on, sometimes only intermittently
  • Light appears or goes out when the driver door is opened or closed
  • Airbag light prevents passing an inspection

How to fix

This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.

On your vehicle

Chevrolet

  • 2010–2013 · Silverado 1500

    Supported by vehicle data

    Owner readouts of B0085 as a left front side impact sensor fault, with an open harness at the driver door; one replaced the sensor with no change.

  • 2015 · Traverse

    Supported by vehicle data

    A shop found B0085:05 current and an open circuit inside the driver door harness.

  • 2007–2008 · Tahoe

    Possible — needs testing

    GM bulletin 4132 covers an SIR light with B0085 through B0088. The NHTSA summary does not say what the codes mean on these model years.

  • 4132 (chevrolet)Status unverified

    SIR light on, DTCs B0085-B0088

    2007–2008avalanche, silverado-1500, silverado-2500-hd, silverado-3500-hd, suburban, suburban-hd, tahoe · issued · NHTSA 10023755

    Covers an SIR light with DTCs B0085, B0086, B0087 and B0088 on 2007-2008 GM full-size trucks and SUVs. The NHTSA summary does not give the cause, the repair or what the codes mean.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • PIT-4662 (chevrolet)Status unverified

    SIR MIL with DTC B0084 and/or B0085

    2003–2007avalanche, suburban, tahoe · issued · NHTSA 10026744

    Covers an SIR indicator with DTC B0084 and/or B0085 on 2003-2007 GM trucks and SUVs, attributed to broken seat position sensor wiring under the front seats. This is a different description than the side impact sensor meaning seen on 2010 and later vehicles.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

GMC

  • 2013 · Yukon XL

    Supported by vehicle data

    Tech tip: B0085 00 left front impact sensor circuit high or low, caused by a corroded kick panel connector (X500).

  • 2020 · Terrain

    Possible — needs testing

    Owner reports an intermittent airbag light with B0085 read by OnStar diagnostics.

  • 2014 · Acadia

    Possible — needs testing

    Independent shop found B0085 together with B0023.

  • 2007–2008 · Yukon

    Possible — needs testing

    GM bulletin 4132 covers an SIR light with B0085 through B0088; PIT-4662 ties B0085 to seat position sensor wiring on 2003-2006 models. The meaning on these older years is not verified.

  • 4132 (gmc)Status unverified

    SIR light on, DTCs B0085-B0088

    2007–2008sierra-1500, sierra-2500-hd, sierra-3500-hd, yukon, yukon-xl · issued · NHTSA 10023755

    Covers an SIR light with DTCs B0085, B0086, B0087 and B0088 on 2007-2008 GM full-size trucks and SUVs. The NHTSA summary does not give the cause, the repair or what the codes mean.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • PIT-4662 (gmc)Status unverified

    SIR MIL with DTC B0084 and/or B0085

    2003–2007yukon, yukon-xl · issued · NHTSA 10026744

    Covers an SIR indicator with DTC B0084 and/or B0085 on 2003-2007 GM trucks and SUVs, attributed to broken seat position sensor wiring under the front seats. This is a different description than the side impact sensor meaning seen on 2010 and later vehicles.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

No curated relationships for B0085 yet.

All Airbags and seat-belt restraints (SRS) codes

B0085 questions

Is it safe to drive with B0085 and the airbag light on?

The vehicle usually drives normally, but manufacturers say the airbags may not work as designed while the light is on, and this fault covers a side crash sensor. Have it checked soon and do not rely on the airbags until it is.

Sources and review

  1. 2023 Accord Owner's Manual: Airbag System Indicators — American Honda Motor Co.
  2. Camry Owner's Manual (OM06291U) — Toyota
  3. Nissan Supplemental Restraint Systems: damage analysis and repair using Diagnostic Trouble Codes (TechNews, Summer 2016) — Nissan North America ,
  4. NHTSA complaint ODI 11210477 (2012 Chevrolet Silverado 1500) — NHTSA Office of Defects Investigation
  5. NHTSA complaint ODI 10871745 (2010 Chevrolet Silverado 1500) — NHTSA Office of Defects Investigation
  6. NHTSA complaint ODI 11704050 (2015 Chevrolet Traverse) — NHTSA Office of Defects Investigation
  7. Yukon Air Bag Light On (2013 GMC Yukon XL tech tip) — ALLDATA
  8. NHTSA complaint ODI 11384441 (2020 GMC Terrain) — NHTSA Office of Defects Investigation
  9. NHTSA complaint ODI 11556823 (2014 GMC Acadia) — NHTSA Office of Defects Investigation
  10. GM bulletin 4132: SIR light on, DTCs B0085, B0086, B0087 and B0088 — NHTSA (General Motors manufacturer communication)
  11. GM bulletin PIT-4662: SIR MIL with DTC B0084 and/or B0085 (seat position sensor wiring) — NHTSA (General Motors manufacturer communication)
Last reviewed
Written by
Saurabh K.
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