Airbag control unit with part number 150300-4670

What is the function of the airbag control unit 150300-4670?

The airbag control unit with part number 150300-4670, a DENSO reference, is the central safety module in the Subaru Legacy BR (2009–2014). It is directly linked to Subaru OEM numbers such as 98221AJ130 or 98221AJ030 and controls the entire restraint system, including all airbags, seatbelt pretensioners, and associated crash sensors.

This control unit (ECU) continuously processes signals from the vehicle’s acceleration sensors. In the event of a collision, it calculates the severity of the impact within milliseconds and determines which restraint systems need to be deployed.

The unit is typically installed deep within the vehicle, usually in the center tunnel near the gearshift lever, to provide optimal protection against external influences and damage during a crash. From this location, it coordinates the deployment of front, side, and head airbags, as well as pyrotechnic seatbelt pretensioners.

Why does the airbag control unit 150300-4670 fail?

The most common cause of failure for the 150300-4670 control unit is the storage of crash data after an airbag or seatbelt pretensioner deployment. Other causes include internal hardware defects due to aging electronic components or moisture ingress, leading to communication failures or specific error codes such as B1877.

Following a crash in which restraint systems have been activated, the control unit locks itself internally. This lock is permanent and cannot be reset using conventional diagnostic tools. The system reports a persistent fault even after replaced components have been installed.

Internal electronic defects are another frequent cause. These may involve faulty solder joints, defective processors, or memory chips (EEPROM). Such issues often render the control unit inaccessible via the OBD interface (no communication).

Occasionally, faults can also occur in specific drive circuits. For example, error code B1877 indicates an open circuit in the driver-side seatbelt pretensioner, which may originate directly within the control unit.

Similar fault patterns can also appear in related part numbers like 150300-2150 or 1503000710, used in comparable Subaru models.

How do you recognize a defect in the 150300-4670 control unit?

A defect in the 150300-4670 control unit primarily manifests as a permanently illuminated airbag warning light on the instrument cluster. Additional indicators include specific error messages on the display, such as “Airbags defective,” and the workshop’s inability to access the control unit via diagnostic equipment (communication failure).

The clearest symptom is the active airbag warning light. It fails to extinguish after starting the engine, signaling a serious, persistently stored fault in the safety system.

In many cases, communication with the control unit becomes impossible. When attempting to read the fault memory, the diagnostic tool receives no response from the airbag ECU.

Depending on the vehicle’s configuration, plain-text error messages may also appear on the information display, including warnings like “Airbags defective” or seemingly unrelated messages such as “Fuel shut-off valve,” which can stem from an internal fault within the control unit.

After a crash, specific errors may also be logged for individual components, such as the passenger airbag or seat-mounted airbags, which remain unresolved despite component replacement.

In which vehicles is the 150300-4670 control unit installed?

The airbag control unit 150300-4670 is primarily used in the fifth-generation Subaru Legacy, specifically in the station wagon model Legacy BR (model years 2009–2014). It is also compatible with models such as the Subaru Outback (BR) and Forester (SJ/SH) from these same years. At Airbag24, we professionally repair these control units.

The core application for this part number lies in the Subaru Legacy V series (BR). A typical example is the Subaru Legacy 2.0 D AWD (BRD), equipped with a 150-horsepower diesel engine and all-wheel drive.

Due to Subaru’s platform strategy, this or a technically very similar control unit can also be found in other models from the same period. Notably:

Subaru Outback (BR, 2009–2014)

Subaru Forester (SJ, 2012–2018 and SH, 2008–2013)

At Airbag24, we specialize in repairing these specific DENSO control units across the entire Subaru model range. Repair offers a reliable alternative to costly new parts.

Is repairing the 150300-4670 control unit worthwhile?

Yes, repair is the most economical and technically sensible solution. Compared to a new unit, which often costs over €500, repair provides significant savings. Additionally, there’s no need for expensive re-coding at a specialized workshop, and you receive a 12-month warranty on the work performed.

The cost of a new airbag control unit from the manufacturer quickly exceeds €500, not including installation and programming fees. Repairing it is significantly more affordable and restores full functionality.

A repaired control unit is “plug-and-play.” Since the original vehicle-specific configuration is preserved, no re‑learning or re‑coding is required after installation—saving time and additional workshop costs.

Purchasing a used control unit carries risks. It’s often unclear whether the donor vehicle also stored crash data or if the unit has other hidden defects. With a professional repair—including a 12‑month warranty—you’re on the safe side.

How does the repair process work at Airbag24?

Once the removed control unit, part number 150300-4670, arrives at Airbag24, our technicians perform a thorough analysis. The repair includes professionally erasing stored crash data and fixing any hardware defects. Finally, full functionality is verified on a test bench.

To ensure a smooth process, we recommend including a brief description of the fault—and ideally the workshop’s diagnostic report—with your package. This speeds up diagnosis.

At Airbag24, each control unit first undergoes an incoming inspection. The core of the repair involves lifting the internal lockout following a crash (resetting crash data) and restoring the software to its factory settings.

If further electronic defects are detected during analysis—such as issues with solder joints or memory chips—these are expertly repaired.

After successful repair, every control unit undergoes a comprehensive functional test to confirm it communicates flawlessly with the vehicle and correctly controls all systems. We provide a 12‑month warranty on the entire repair.

What shipping options does Airbag24 offer?

You can easily send us your defective control unit or bring it in person. Alternatively, you can arrange convenient UPS pickup at your preferred location. For returns, we offer free standard UPS shipping as well as faster express options, including cash-on-delivery.

For outbound shipments, you have two choices: ship the package yourself or use our pickup service. Simply book UPS pickup online, and a courier will arrive at your address with a pre‑printed shipping label.

Your repaired control unit is returned free of charge via standard UPS shipping within 1–3 business days.

If you need it sooner, you can opt for UPS Express delivery (delivered in 1–2 business days). Both standard and express shipping are available with cash-on-delivery as well.

Of course, you can also pick up your repaired control unit in person once the repair is complete.