OBD-II trouble code
B0048: Third Row Right Side Airbag Deployment Control (Subfault)
The mirror of the left-side code, on the corner of the vehicle that gets used the most. Whether this code appears alone or alongside its left-hand twin is the single most useful piece of triage available, and it decides whether you open a seat or go looking upstream.
Quick facts
- System
- Body
- Category
- Airbag / SRS Restraints
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $1,200
- DIY difficulty
- Shop recommended
What does B0048 mean?
The right-hand third-row torso bag is functionally identical to the left one, so rather than repeat the description, this page is about the two things that are genuinely specific to this position: how the corner is used, and what the code's companions tell you.
Start with companions, because it saves the most time. Each deployment loop is electrically independent — its own pair of wires, its own connector, its own squib — but they are not independent all the way back. They share the restraints module, the module's connector, a common ground, and often a harness run that passes through the same rear crossmember and the same body-to-seat junction. That structure gives you a rule worth applying before any disassembly. Two side-airbag codes together, B0048 alongside B0040, point at what those loops share, because two pyrotechnic devices failing simultaneously is close to unheard of while one damaged harness section or one module connector explains both at once. B0048 alone points at what the loops do not share, which is this seat, this connector and this bag. Reading the code list that way routinely turns a two-seat teardown into a single junction inspection.
The second point is about wear. In left-hand-drive markets the right side is the curb side, and the third-row right corner is the busiest part of the interior. It is where people reach in from the sidewalk, where the seat is folded and raised most often to reach the cargo area, and where child seats are loaded because parents prefer to work from the kerb rather than the road. Whatever fatigue the seat harness experiences, it experiences more of it here. So when this code turns out to be mechanical, expect worn or fatigued rather than corroded — a routing clip broken by repeated cycling, a connector walked out of its lock, an insulation crack at a fold point.
There is one more thing about this corner that catches people out. The right rear quarter is where a great many factory and aftermarket audio amplifiers, subwoofers and accessory power points are installed, because there is usable void space behind the trim panel. Any of that work means someone had a trim panel off within inches of a restraints harness, and a B0048 with an install history nearby is worth investigating there before anywhere else.
As with any deployment loop, this is a protection fault rather than a driveability fault, and the circuit contains a live pyrotechnic device. Diagnosis belongs with a technician equipped to disable the system properly.
Common causes
- Fatigued or broken routing clip on the curb-side seat, which is cycled more often than its left-hand counterpart
- Seat-base connector unlocked by repeated folding for cargo and passenger access
- Restraints harness disturbed during amplifier, subwoofer or accessory power installation in the right rear quarter
- Shared fault upstream at the module connector or common ground, which will normally set the left-side code as well
- Cracked insulation at a seat-frame fold point after years of use
- Failed inflator squib in the right seat-mounted side airbag module
- Damage to the yellow SRS connector or its shorting bar during a previous seat removal
- Restraints control module fault, worth considering only once the seat-side wiring is proven good
Symptoms
- SRS or airbag warning lamp on continuously
- B0048 stored in the restraints module, with or without B0040 as a companion
- Fault that correlates with folding or raising the right third-row seat
- Code that first appeared after audio or accessory installation in the right rear quarter
- Intermittent setting after heavy cargo loading through the tailgate
- No effect at all on engine performance, transmission behaviour or braking
- Other airbag positions functioning normally, since each loop is separately monitored
- Nothing externally visible, as both the bag and its harness are concealed within the seat
Diagnostic steps
- 1.Read the complete stored code list before anything else and note whether the left-side code is present too. Two side codes together move the search upstream to the module connector, common ground and shared harness run; B0048 by itself keeps the search inside this seat. That decision alone often halves the job.
- 2.Ask whether anything has been installed in the right rear quarter — an amplifier, a subwoofer, an inverter, an accessory socket. That trim panel sits directly alongside the restraints harness, and a fault dating from that work has an obvious first place to look.
- 3.Confirm from build data that a third-row side airbag is actually fitted to this vehicle, since option content varies within the same model line and module code tables cover configurations the vehicle may not have.
- 4.Disable the restraints system by the manufacturer's procedure and observe the specified waiting period for the reserve capacitor to discharge before disconnecting anything.
- 5.Work the seat through folding and raising while the circuit is monitored, then inspect the harness at each point where it changes shape. This corner sees more cycles than any other seating position, so fatigue damage is both more likely and easier to find once you know where to look.
- 6.With wiring and connector cleared, measure loop resistance against specification using the approved restraints tester to separate a harness fault from a spent or failed inflator. An ordinary multimeter must never be connected across a deployment loop.
Repair cost
$100 – $1,200
Where the fault is a shared upstream connector — the likely case when both side codes are present — the repair can be as simple as reseating and cleaning a module plug, at little more than diagnostic cost. SRS diagnosis runs $110 to $210. Seat harness repair typically lands at $180 to $500 since the seat has to be removed. A seat-mounted side airbag assembly is $400 to $1,000 fitted and is generally supplied together with part of the seat back trim rather than as a bare inflator. Module replacement with programming adds several hundred dollars on top.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with airbag control module (sdm) replacement / reset 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.