Airbag control unit with part number 1521004560

What is the function of the airbag control unit 1521004560?

The airbag control unit 1521004560 from Autoliv is the central control module for the occupant restraint system (SRS) in various Toyota models. It processes signals from crash sensors, determines when to deploy airbags and seatbelt pretensioners, and continuously monitors the functionality of all safety‑related components.

As the “brain” of the passive safety system, this control unit—also known by the identical part number 152100-4560—is responsible for evaluating data from acceleration and pressure sensors throughout the vehicle.

In the event of a collision, the module decides within milliseconds which restraint systems—such as front, side, or knee airbags, as well as pyrotechnic seatbelt pretensioners—should be activated to provide optimal protection for occupants.

In addition, the control unit performs a self‑test at every vehicle start-up and continuously monitors all connected components. If it detects a fault in the wiring, a sensor, or its own internal electronics, it illuminates the airbag warning light.

Why does the airbag control unit 1521004560 fail?

The most common cause of failure for control unit 1521004560 is the storage of crash data after an accident, which prevents further use. In addition, internal electronic defects in components such as ICs, memory chips, or the power supply can lead to malfunctions and communication failures.

After an accident in which airbags or seatbelt pretensioners have deployed, the control unit stores these events as “crash data” in its internal memory. This lockout is a manufacturer‑imposed safety feature that ensures the vehicle cannot be operated with a potentially compromised system. The airbag warning light then cannot be cleared using a diagnostic tool.

Even without an accident, purely electronic faults may occur. Defective components on the circuit board—such as driver stages, memory chips (EEPROM/Flash), or parts of the internal power supply—are typical sources of failure. Causes include aging, moisture, or voltage spikes in the vehicle’s electrical system.

In some cases, the high current flow during airbag deployment not only results in crash data being stored but also damages sensitive electronic components on the circuit board. A professional repair therefore addresses both potential causes of failure.

How do you recognize a defect in control unit 1521004560?

A defective control unit 1521004560 is primarily indicated by a permanently illuminated airbag warning light on the instrument panel. Additional symptoms include the inability to communicate with a diagnostic tool and error messages such as “Check Airbag / SRS” displayed on the vehicle’s screen.

The clearest sign is the active airbag warning light (SRS light), which fails to turn off after the engine starts. It may either remain steadily lit or, in some cases, flash intermittently.

Another critical symptom is complete loss of communication. If the workshop cannot access the airbag control unit with a diagnostic device, this strongly suggests an internal hardware fault within the module itself.

After an accident, a persistently lit warning light is normal because crash data has been stored. Attempts to clear the fault memory will fail until the data has been professionally erased.

Additionally, text messages such as “Check Airbag / SRS” may appear on the instrument cluster. The vehicle’s fault memory may also contain codes indicating an internal control unit malfunction or specific issues with components like side airbags or seatbelt pretensioners.

In which vehicles is control unit 1521004560 installed?

The Autoliv airbag control unit 1521004560 is primarily used in various generations of the Toyota Aqua NHP10. At Airbag24, this control unit is also successfully refurbished for the Toyota Vellfire Hybrid and the Toyota Proace City.

At Airbag24, we offer expert repair services for the airbag control unit 1521004560 for the following Toyota models:

Toyota Aqua NHP10 (2011–2015), NHP10 First Facelift (2015–2017), and NHP10 Second Facelift (2017–2021)

Toyota Vellfire Hybrid

Toyota Proace City

How does the repair of 1521004560 proceed at Airbag24?

After removal and shipment of control unit 1521004560 to Airbag24, a comprehensive diagnosis is performed on the test bench. Depending on the findings, stored crash data is deleted and/or defective electronic components are replaced. A final functional test confirms the quality of the repair.

Before removal, a specialized workshop should read the fault memory to confirm that the defect lies in the control unit itself and not in external components such as sensors, the seat occupancy mat, or the wiring.

Send the removed control unit, well-packaged, to Airbag24. Upon receipt, the unit will be connected to specialized test benches for Autoliv control units to identify the exact fault—whether it’s a simple crash-data lockout or a more serious hardware defect.

Our technicians will then perform the necessary repairs, which may involve completely resetting the crash data or replacing defective components on the circuit board through chip-level soldering.

After repair, each control unit undergoes a final functional test to verify proper operation. Every repair comes with a 12-month warranty.

What shipping options does Airbag24 offer?

You can either send your defective control unit to Airbag24 yourself at no cost, or arrange a convenient UPS pickup. For return shipping, you have the choice between free standard UPS shipping and faster express options. Cash-on-delivery and self-collection are also available.

For outbound shipping, you have two options: you can ship the package yourself free of charge, or use the convenient UPS pickup service, which collects the package directly from your preferred location.

The return shipment of the repaired control unit is provided free of charge by default via standard UPS shipping. If you need it faster, you can optionally select UPS Express shipping. Both shipping methods can also be combined with cash-on-delivery.

In addition, upon prior arrangement, you can personally pick up your repaired unit at our premises.