OBD-II trouble code
B009F: Right Side Restraints Sensor 6 (Subfault)
A fault on right-side impact sensor 6. Whether this code arrived on its own or with satellite faults from elsewhere in the car decides the whole diagnosis, because on many systems all the satellites hang off one shared link and a single break silences several at once.
Quick facts
- System
- Body
- Category
- Airbag / SRS Restraints
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $900
- DIY difficulty
- Shop recommended
What does B009F mean?
B009F is stored by the airbag control module against the sixth satellite impact sensor on the right side of the vehicle. It is a hexadecimal code — the final character is the letter F. Satellite sensors are small accelerometers distributed through the doors, pillars and rocker structure that report the severity and direction of a side impact so the module can decide what to deploy.
Start by reading every fault in the restraints module rather than this one, because the pattern is what tells you whether you are looking for a sensor or a circuit.
B009F stored alone, with no other satellite faults, is the straightforward case and points at something local: that sensor, its connector, its mounting, or the short length of harness serving it.
B009F stored together with satellite faults on the other side of the vehicle, or at several stations, is a different problem entirely and it should stop you buying sensors. Accelerometers mounted metres apart, in different structural members, do not fail simultaneously. What they have in common is a supply, a ground, and — on a large number of modern systems — a shared communication link. Many manufacturers no longer wire satellites as individual analogue sensors. Instead they run them on a dedicated two-wire serial bus from the restraints module, with the sensors addressed on that link. A single break, a corroded splice, or a short anywhere on that link takes out every sensor downstream of it, and the module dutifully logs a fault against each one it can no longer hear. Six codes, one broken wire. Diagnosing that as six bad sensors is a way to spend well over a thousand dollars and still have every code stored.
So the question to answer before anything is unbolted is which architecture this vehicle uses. If the satellites share a serial link, find where the link branches and test from there outward. If they are individually wired, the shared elements are only the supply and the ground, and those are still worth checking first.
The second thing worth knowing concerns how this circuit tends to get damaged, and it usually has nothing to do with a collision. A sixth-station satellite typically lives well back in the vehicle — rear door, C-pillar, rocker or rear quarter area — behind trim that comes off for reasons that have nothing to do with restraints. Aftermarket audio installation in the rear quarter is the most common by a distance: amplifiers, subwoofers and their power runs go exactly where this harness lives, fitted by people with no reason to know a restraints circuit passes through that panel. Beyond audio, the same applies to trailer wiring, cargo lighting, tracking and telematics devices, load-area shelving in vans, and mobility conversions. If the trim in that area has been off, ask what for. A pierced, pinched or tapped restraints circuit is a real and repeatable cause here, and it is found by inspection rather than by measurement.
Third, sensor mounting deserves a look rather than an assumption. A satellite that is loose, cross-threaded, fitted with the wrong fastener or packed against sound-deadening rather than sitting flat on structure is not properly coupled to the bodyshell. It can test perfectly on resistance and still report a signal the module rejects as implausible.
The car drives normally, but right-side impact protection may not perform as designed. Airbag systems contain pyrotechnic devices and must be safely disabled before any of this work begins.
Common causes
- Break, corrosion or short on the shared satellite communication link, which silences several sensors at once
- Shared supply or ground fault affecting multiple satellites across the vehicle
- Harness pierced, pinched or tapped during aftermarket audio, trailer, lighting or telematics installation in the rear quarter
- Corroded or water-intruded connector at the right-side satellite sensor
- Failed satellite sensor reporting an internal fault
- Sensor loose, cross-threaded or not seated flat against structure, giving an implausible signal
- Trim panel refitted with a clip or screw through the harness
- Rear door or rocker harness chafed where it flexes
- Previous body repair on the right side that disturbed the sensor or its wiring
Symptoms
- Airbag or SRS warning light illuminated
- B009F stored with a symptom byte in the restraints module
- Several satellite sensor codes stored together across different areas of the vehicle
- No effect on engine, braking or handling
- Fault appearing shortly after audio, trailer wiring or accessory installation work
- Intermittent fault that changes with rear door movement or over rough road surfaces
- Code that clears and returns without any obvious trigger
Diagnostic steps
- 1.Read every fault stored in the restraints module before touching anything, since the pattern of which satellites are complaining is the fastest route into this code.
- 2.If satellites at several stations or on both sides have logged faults together, stop and investigate the shared circuit — sensors metres apart do not fail on the same day.
- 3.Establish whether this vehicle wires its satellites individually or runs them on a shared two-wire serial link, because that determines where the shared fault can be.
- 4.Where a shared link is used, find the point at which it branches and test outward from there rather than at each sensor in turn.
- 5.Ask what work has been done in the rear quarter or rear door area — audio installation, trailer wiring, cargo lighting, telematics and load-area fittings all put fasteners and cable runs through this harness.
- 6.Remove the relevant trim with the system safely disabled and inspect visually for pierced insulation, added splices, clips driven through the loom and taped-in accessory wiring.
- 7.Check the sensor mounting: correct fastener, correct torque, sitting flat against structure and not packed against sound-deadening.
- 8.Inspect the connector for moisture, corrosion, terminal tension and backed-out pins.
- 9.Verify supply and ground at the sensor against specification before condemning the sensor itself.
- 10.Repair to the manufacturer's specification using approved connectors, then clear the fault and confirm it stays clear through an ignition cycle and a road test.
Repair cost
$100 – $900
SRS diagnostic time is $100 to $220 and needs a tool capable of reading the restraints module properly. Undoing an accessory installation that pierced or pinched the harness, and repairing it correctly, is $150 to $450 including trim removal and refitting. A satellite impact sensor is $60 to $260 in parts, generally $200 to $550 fitted with the required system checks. A fault on the shared satellite link is $180 to $500 to locate and repair. The expensive mistake specific to this code is treating multiple simultaneous satellite faults as multiple failed sensors — that is $600 to $1,500 of parts spent on a single broken wire, with every code still stored afterwards.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with airbag / srs crash sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.