Airbag control unit with part number Y851M-EH001

What is the function of the airbag control unit Y851M-EH001?

The airbag control unit Y851M-EH001 is the central control module of the occupant restraint system (SRS) for the Infiniti M45 of the Y50 series. It processes signals from crash sensors to precisely deploy airbags and seatbelt pretensioners at the right moment during a collision, thereby ensuring the safety of vehicle occupants.

Technically, this control unit—also known as the SRS Control Unit—is responsible for continuously monitoring the entire system. It checks the functionality of all connected components, such as airbags, seatbelt pretensioners, and sensors. If any irregularities are detected, the SRS warning light in the cockpit illuminates immediately, alerting the driver to a potential system failure.

This module is specifically designed and mapped for the Infiniti M45 Y50 (model years 2005–2010) to ensure precise compatibility with the vehicle’s architecture. It is compatible with components from established automotive manufacturers such as Denso or Bosch.

Why does the Y851M-EH001 control unit fail?

The most common causes of failure for the Y851M-EH001 control unit include stored crash data after an accident, which locks the device, as well as physical damage caused by moisture, water ingress, or voltage surges. Internal electronic malfunctions or faulty connectors can also lead to failure.

After a collision, the control unit permanently stores crash data. This lock serves as a safety feature, preventing reuse without professional diagnostics and reset procedures. In many cases, repair is possible by erasing this stored data.

Another frequent cause is environmental exposure. Penetrating moisture or water damage leads to corrosion on the circuit board and damages sensitive electronic components. Similarly, voltage surges—such as those occurring during jump-starts—or mechanical damage to cables and connectors can impair functionality.

Internal faults within the control unit itself are also a typical issue. These often manifest as error codes like 65535 or 93F9 (both indicating “internal control unit fault”) or B1000, which signifies a complete communication breakdown. Such problems affect both part number Y851M-EH001 and its related variant K851M-EH001.

How do you recognize a defect in the Y851M-EH001?

A defect in the Y851M-EH001 control unit primarily shows up as a constantly illuminated or flashing airbag warning light (SRS light) in the instrument cluster. Additional symptoms include loss of communication with diagnostic equipment and specific error codes indicating an internal malfunction.

The most obvious sign is the activated SRS warning light, signaling that the restraint system is not functioning properly—a serious threat to driving safety. Immediate inspection at a workshop is essential in such cases.

A more severe symptom occurs when the control unit becomes unresponsive via the OBD interface. Diagnostic tools, such as the iCarsoft CR PRO, cannot establish a connection, often documented by error code B1000.

If error codes like 65535 or 93F9 are read, they directly point to an irreparable internal hardware failure. In this state, the system is completely disabled.

In which vehicles is the Y851M-EH001 installed?

The airbag control unit with part number Y851M-EH001 is specifically designed for Infiniti models. It is mainly used in the Infiniti M45 of the Y50 series, produced between 2005 and 2010. Airbag24 offers repair services for these specific vehicles.

At Airbag24, we repair control units with part numbers Y851M-EH001 and its related identifier K851M-EH001 for the following models:

Infiniti M45 Y50 (model years 2005–2010) Infiniti Premium M45

How is the Y851M-EH001 control unit professionally repaired?

Professional repair at Airbag24 includes precise diagnostics to identify the fault, targeted correction of the root cause—such as erasing crash data or replacing defective components—and final functional testing. This restores full operability to the control unit.

Upon submission to Airbag24, the control unit undergoes a standardized repair process. First comes an initial analysis, where the fault memory is read to determine the exact cause—whether it’s an internal defect or stored crash data.

Next follows the actual restoration. Specialized technicians erase crash data or perform component-level repairs on the electronics. Defective parts are replaced with new, high-quality components.

Finally, the control unit is thoroughly tested to ensure it communicates flawlessly again and performs all functions correctly. We provide a 12-month warranty on every repair.

What shipping options does Airbag24 offer?

For convenient processing, Airbag24 offers flexible shipping options. You can send your defective control unit back to us free of charge yourself or arrange a convenient UPS pickup. Returns are shipped free of charge via UPS Standard, with an optional Express service—including cash-on-delivery.

For sending your item back, you have two choices: either ship the package to us yourself, or schedule a UPS pickup at a location and date of your choosing. Personal drop-off at our facility is also available.

The return shipment of your repaired control unit is standardly free of charge via UPS Standard, with a delivery time of 1–3 business days. If you need it faster, UPS Express (1–2 business days) is available. Both options can also be arranged with cash-on-delivery. Alternatively, you may choose to pick up the device from us in person.