Airbag control unit with part number K8820-1MX0B

What does the airbag control unit K8820-1MX0B do?

The airbag control unit K8820-1MX0B is the central control unit of the restraint system in Infiniti. It evaluates the impact signals, determines the triggering of airbags and seatbelt pretensioners within milliseconds in a crash, and monitors the system continuously.

If it detects a fault, it indicates this on the airbag warning light. After an accident it stores crash data and locks itself; only the repair lifts the lock.

Why does the control unit K8820-1MX0B fail?

Stored crash data is the most common cause for the K8820-1MX0B, even if no airbag has deployed; a normal diagnostic tool cannot erase it. Further causes are ageing components, cold solder joints, moisture and corrosion at plugs, as well as voltage spikes.

Which of the remaining factors applies only becomes clear when the unit is examined. Voltage spikes arise, for example, from a weak battery or jump-starting, and moisture can attack plug connections over time.

How can you tell that the K8820-1MX0B is defective?

You can recognise a defect in the K8820-1MX0B mainly by the airbag warning light in the instrument cluster, which lights up permanently or intermittently. In addition there may be an error message, no connection to the diagnostic tool, and a fault memory that cannot be cleared.

These signs at a glance:

• Airbag warning light, permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool without connection to the control unit
• Fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may then fail to deploy. A prompt check is therefore advisable.

Which vehicles is the K8820-1MX0B fitted in?

The K8820-1MX0B is fitted in these vehicles: Infiniti M35 Y51 (2010-2013).

Here is the overview for this part number:

• Infiniti M35 Y51 (2010-2013)

Two points need attention here. Comparing the part number on the label of the removed unit with this page only ensures that it is the correct unit. Reading out the fault memory, on the other hand, shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 98820-1MX0B, K8820-1MR1A.

How does the repair of the K8820-1MX0B work?

Airbag24 needs 3–4 working days in the normal course for testing, repair and function test. During this time the team erases the stored crash data before the function test runs.

Before sending, you read out the fault memory and enclose the log. Only then do you disconnect the battery and remove the control unit; afterwards you create the repair order online.

After processing, your own unit comes back. Our repairs come with 2 years' statutory liability for defects. The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit K8820-1MX0B get to Airbag24?

You send the K8820-1MX0B as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

The printed repair order belongs in the parcel, and the unit must be packed shockproof.