By iCarsoft Official Store Technical Team, Automotive Diagnostics Editors · Updated October 18, 2026 · Technical sources checked
Quick Answer
B0073 depends on the OEM: verified GM material names a passenger belt-switch circuit, while Stellantis identifies a second-row buckle pretensioner channel. It does not prove a failed buckle or a universal low-resistance loop. Save the original full code and have a qualified technician confirm the actual circuit and physical side before repair.
What Does the B0073 Code Mean?
B0073 has different verified OEM meanings. GM TechLink calls it Passenger Seat Belt Switch Circuit in its Equinox/Terrain example. Stellantis S2408000077 instead defines B0073 suffixes as second-row left seatbelt buckle pretensioner deployment control. The reporting module, equipment and complete code must decide which meaning applies. The full fault record determines the test branch.
A buckle switch reports belt status; a pretensioner loop supervises a pyrotechnic device. Normal switch data cannot certify the firing circuit. These functions require different diagnosis.
B0073 does not identify one universal seat. Resolve the controller, equipment and full OEM descriptor before tests or parts. Older supplemental-loop wording cannot override the verified GM and Stellantis applications.
A descriptive lookup is insufficient when two primary OEM sources assign different functions. Save the original controller wording and suffix. A GM passenger switch diagnosis must not be copied into a Stellantis pyrotechnic loop, and the older supplemental-loop label cannot override either verified application.
GM TechLink, September 2022, page 4, explicitly supplies the passenger belt-switch definition. GM 22-NA-170, revised September 12, 2023, describes a scoped tail-lamp water-migration concern and a B0073-specific seat/body connection branch. The water route is an application-specific possibility, not proof that every B0073 comes from a rear lamp.
Stellantis S2408000077, released July 2024, explicitly defines B0073-11/-12/-13/-2B pretensioner subtypes. A limited ORC mapping issue can display the opposite side. Confirm the stated model/module applicability and current guidance before locating the physical fault; do not universally reverse sides.
Save the full module wording and suffix before clearing; they can change the test path.
Separate B0073 from adjacent fault families
| Code | General description | Key distinction |
|---|---|---|
| B0073, GM example | Passenger Seat Belt Switch Circuit | Verified GM TechLink application; not a universal pretensioner definition. |
| B0073-11/-12/-13/-2B, Stellantis | Second-row left buckle pretensioner control subtypes | Ground, battery, open and wires-together classifications require their own branch. |
| B0075, Stellantis case | Second-row right buckle pretensioner channel | Scoped software mapping issue requires applicability checks before physical-side diagnosis. |
| P12A6, GM bulletin | Fuel-pump driver enable circuit performance | A separate water-related branch; it does not define B0073. |
Record the complete B0073 description. The suffix, reporting module and companion faults can change the diagnostic path. Use the manufacturer's full wording and test procedure for the exact vehicle.
B0073 Symptoms and Likely Causes
Record B0073 symptoms and fault status; symptoms alone cannot identify a failed part.
Check whether companion faults share a proven cause.
Record the exact warning and reporting module. Belt reminder behavior does not identify which B0073 implementation the vehicle uses.
On a matching GM application, note rear-lamp damage, visible moisture and related service history. Do not unplug seat/body restraint connections to look for corrosion.
Save the unedited OEM description. The limited Stellantis mapping case requires current applicability checks; an owner should not move parts or reverse sides experimentally.
A normal latch or switch reading cannot validate every B0073 circuit. A pretensioner fault may exist independently of ordinary belt engagement.
Practical cause-checking order
- OEM and suffix identity: A generic lookup can misidentify the function. Confirm the full OEM descriptor before interpreting B0073 as a switch input, low-resistance loop or pretensioner channel.
- External connection: The affected interface and permitted tests depend on the actual circuit. A switch-input test cannot be reused on a pyrotechnic path.
- Application-specific water route: The scoped GM water-migration lead requires matching vehicle and evidence. B0073 alone cannot justify replacing a rear lamp or identify water damage.
- Scoped software mapping: The limited Stellantis side-mapping concern requires exact model/module applicability and current guidance. It does not authorize opposite-side repairs on every vehicle.
- Proven component failure: Switch, pretensioner or controller replacement requires OEM isolation evidence. The base code cannot establish which assembly failed or whether buckle replacement restores the function.
Did B0073 appear after recent belt, seat/body harness, rear-lamp, ORC or collision work? Recheck the documented connections, parts and setup steps affected by that work. Record battery and software history; a post-repair code does not prove the new part is defective.
How Serious Is B0073, and Can You Drive?
Arrange qualified OEM diagnosis and follow the owner's manual and VIN-specific recalls. B0073 cannot certify remaining protection or safe travel. Stop use for an unusable belt, deployed restraint, smoke/heat, damaged wiring or abnormal control.
Record warning messages, operating conditions and service history. Do not induce wheel slip, emergency braking or a handling event on public roads. A red stop warning or abnormal control overrides any verification plan.
Stop and arrange a tow if there is crash damage, a deployed restraint, smoke, heat, damaged safety wiring, an unusable belt or a vehicle stop warning.
Some B0073 meanings directly concern a pyrotechnic pretensioner. Do not use the GM switch label to justify probing a deployment path, fitting resistors, bridging wires, applying voltage or activation. No crash-data erasure is advised. Exact SRS isolation and re-enabling require qualified OEM procedures.
How to Diagnose B0073 in the Right Order
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Save the original OEM wording and suffix
Save the full supported module report, exact B0073 wording, suffix, status, controller identity and companions before clearing. Record belt, seat, lamp or module work. Preserve uncertainty about crash and water history instead of inventing an event.
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Identify switch or pretensioner architecture
Use current VIN-specific information to determine whether B0073 concerns the GM switch circuit, a Stellantis pretensioner channel or another implementation. Identify equipped devices and connector views. Do not treat the base number as a universal location.
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Match the actual application and route
For a matching GM vehicle, have the technician assess the bulletin's water path. For the Stellantis case, confirm its exact model/module mapping applicability. Do not transplant connector locations, component names or opposite-side guidance between these architectures.
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Require the correct safe diagnostic branch
Require the qualified procedure for the identified circuit. A switch-input label does not authorize deployment-terminal probing elsewhere. No generic resistance test, jumper, bypass, battery feed or discharge timer is supplied; pyrotechnic paths require approved non-deployment equipment.
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Confirm physical side and failed section
Ask what proves the actual physical side, failed connection or component and any contributing water/software issue. Supported switch live data is evidence about that input only. Missing scanner coverage cannot prove vehicle failure or replace required OEM diagnosis.
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Verify the corrected circuit and cause
Complete the evidence-supported correction, required setup and qualified non-deployment checks. Save the final full-code record and approved original-condition results. A dark warning cannot alone establish the correct side, repaired water source or restored pretensioner function.
Specifications are vehicle-specific. Use the exact VIN specifications, approved test points and required operating state. No generic value or drive cycle can replace the applicable procedure. Manufacturer examples here do not establish specifications for other applications.
B0073 Repairs and Cost Planning
A B0073 repair must address the demonstrated failure. Do not replace an assembly from the code alone.
Recheck installation and required setup after repair. Correct the demonstrated branch and its cause. In a confirmed water-intrusion case, repairing a damaged connection without addressing the source can leave recurrence risk. In a scoped mapping case, the technician must establish the proper physical side through current OEM guidance before choosing hardware.
Ask the shop to name the failed branch and the measurement supporting each proposed repair.
Authorize diagnosis before parts while the cause remains uncertain.
| Possible path | Quote basis |
|---|---|
| Proven OEM-permitted repair of the actual belt-switch or restraint connection | VIN-specific quote |
| Confirmed affected harness repair and water-source correction when demonstrated | VIN-specific quote |
| Correct switch, pretensioner or controller service only after OEM isolation | VIN-specific quote |
| Applicable current configuration guidance, non-deployment prove-out and final report | VIN-specific quote |
These are alternative repair paths, not prices to add together. Request a VIN-specific quote separating diagnosis, parts, labor, fluids, taxes, required setup and verification. Ask which failed test supports the proposed repair and whether warranty coverage applies.
Using iCarsoft CR Pro S for B0073
On a supported vehicle, iCarsoft CR Pro S can save accessible faults, available freeze frame, live data and diagnostic reports. Preserve the B0073 evidence before clearing.
Compare the saved and final module records. Scan data supports diagnosis but does not replace the OEM reference, physical measurement or safety-system functional check.
Preserve the OEM-specific restraint circuit evidence
iCarsoft CR Pro S
Review supported codes and relevant live data together. Confirm the exact VIN, controller access, PIDs with iCarsoft before purchase; generic product capabilities do not guarantee a B0073-specific function.
Check current CR Pro S price and availabilityCheck CR Pro S compatibility by VINThe official product page describes supported full-system diagnostics, available live data, freeze frame and diagnostic reports; exact ECU access and non-deployment functions depend on the VIN and software. Confirm the requested function by VIN before purchase. Follow OEM prerequisites and stop for abnormal operation.
Know the measurement boundary. Scan data describes ECU-provided information; it does not directly prove the physical condition of the OEM-specific restraint circuit. Where required, use qualified OEM circuit equipment and non-deployment SRS procedures for the identified architecture and compare reported values with the relevant measured evidence.
Verify the B0073 Repair
After repair, verify installation, clearance and required setup. Save the final findings and clear only erasable records as instructed. Battery disconnection is not a repair.
Use the manufacturer's non-deployment post-service restraint checks in a qualified workshop. Compare the original operating state with current data for the OEM-specific restraint circuit, and check current and pending faults in related modules. A clean start or idle period does not prove the repair; use the OEM functional check for the affected system.
Compare the original and final fault status. Record the functional-check result and whether the original event returned.
If B0073 returns, compare its suffix, status, failure order and operating conditions with the saved baseline before replacing another part. Revisit the failed branch and inspect anything disturbed. Confirm the prescribed affected-system functional verification separately from code clearing.
Verification follows the system involved. After saving the original evidence, use the OEM procedure to clear erasable records, complete any required calibration or functional check, and compare the final module status with the original warning and fault conditions.
Related OEM-Specific Restraint Circuit Code Guides
Compare the related monitor families below. Shared symptoms or components do not make their repair procedures interchangeable.
B0073 Frequently Asked Questions
Why does B0073 have different seat-belt descriptions?
Verified OEM documents assign different functions: a GM passenger belt-switch circuit and a Stellantis second-row buckle pretensioner channel. The full code, reporting controller and exact vehicle decide which applies. Do not use an older supplemental-loop description or universally reverse sides based on the limited Stellantis software case.
What should I check first for B0073?
Save every module's codes and freeze frame before clearing. Confirm the full definition, suffix and VIN architecture. Then inspect recent belt, seat/body harness, rear-lamp, ORC or collision work, connectors and shared supplies. Those facts determine whether the next test needs qualified OEM circuit equipment and non-deployment SRS procedures for the identified architecture or a qualified non-deployment restraint procedure.
Can I drive with the B0073 code?
Arrange qualified OEM diagnosis and follow the owner's manual and VIN-specific recalls. B0073 cannot certify remaining protection or safe travel. Stop use for an unusable belt, deployed restraint, smoke/heat, damaged wiring or abnormal control.
Why did B0073 return after a part was replaced?
If B0073 returns after buckle replacement, recheck whether the original definition, physical side and external path were established. A switch part may not address a pretensioner channel; a connection repair may not remove its water source. Compare complete records and applicable software guidance before replacing another assembly.
What should a B0073 repair estimate include?
Ask for the failed-test evidence and a VIN-specific breakdown of diagnosis, parts, labor, taxes, required setup and verification. A code alone cannot establish the repair price.
Can CR Pro S diagnose and clear B0073?
On a supported vehicle, CR Pro S can organize available faults, freeze frame, live data and reports, and can clear erasable records after repair. Confirm exact ECU coverage. It must not be used to deploy, bypass or erase crash data and cannot replace the qualified OEM procedure for the OEM-specific restraint circuit.
The iCarsoft Official Store Technical Team maintains the store's fault-code library. This guide organizes published technical references and verified product information; it does not document a hands-on test of a particular vehicle or claim an individual engineer's review.
Technical and cost references
- GM TechLink — September 2022, Volume 24, No. 17 — Tail Lamp Water Leak. Page 4 explicitly defines B0073 as Passenger Seat Belt Switch Circuit in its stated example.
- GM 22-NA-170 — Information on Possible Crank No Start or Extended Crank with DTC P12A6 or Service Safety Restraints message on DIC, with B0073. September 2023; revised September 12, 2023. Scoped application and B0073 seat/body connection branch.
- Stellantis S2408000077 — Air Bag Module Sets Left or Right Rear Seatbelt Buckle Pretensioner Faults. Released July 2024; explicit B0073 subtypes and limited opposite-side diagnostic mapping concern. Not a universal repair or warranty authorization.
- Gunson Instruction 77031 — Historical B-code table. Undated, printed page 7; older supplemental-loop wording cannot override verified OEM applications.
Product information: Official iCarsoft CR Pro S page.
Editorial note: General diagnostic education, not a substitute for the owner's manual, current VIN-specific service information or professional inspection. Test limits, procedures, coverage and costs vary. Related articles provide context; apply only the specifications and repair procedures that match the vehicle. No universal failure rate, repair price or outcome is implied.
