Airbag control unit with part number 89170-48550

What does the airbag control unit 89170-48550 do?

The control unit 89170-48550 is the airbag control unit of the restraint system (SRS) for Lexus. It processes the signals from the crash sensors, decides within milliseconds in a crash whether airbags and seatbelt pretensioners are triggered, and monitors the entire system. If it detects a fault, it shows it via the airbag warning light.

Monitoring runs continuously as soon as the vehicle is powered. Measured values are compared with one another constantly during this process.

After a crash, the unit stores crash data and locks itself.

Why does the control unit 89170-48550 fail?

The most common cause is crash data from an accident, even if no airbag has deployed; an ordinary diagnostic tool cannot remove it. Further causes are aged components, cold solder joints, moisture and corrosion on plugs, and voltage spikes, for example from a weak battery or a jump start.

An impact without deployment still leaves entries in the memory. The presence of the data therefore says nothing about whether an airbag has responded.

Aged components gradually lose their reliability. Cold solder joints and moisture in the plugs disrupt signal transmission, and voltage spikes additionally affect the electronics.

How can you tell that the 89170-48550 is defective?

The airbag warning light in the instrument cluster indicates the defect by staying on permanently or intermittently. In addition, a fault message may appear in the instrument cluster, or the diagnostic tool cannot reach the control unit. In that case, airbags and seatbelt pretensioners may fail to trigger in an emergency.

The light indicates a fault even when the vehicle behaves inconspicuously in everyday use. So a defect is not only shown by the light, but also by the fault message and the disrupted communication with the diagnostic tool.

A check is sensible in any case as soon as the light or a message appears. Only the readout reveals the cause.

Which vehicles is the 89170-48550 fitted in?

The control unit 89170-48550 is fitted in these vehicles: Lexus RX AL10 Facelift (2012-2015) and AL10 (2009-2012). The stored assignment of this part number is decisive.

Below you will find the list of stored vehicles.

• Lexus RX AL10 Facelift (2012-2015)
• Lexus RX AL10 (2009-2012)

Before that, compare the part number on the label of the removed unit with this page; this only confirms that it is the correct unit. Additionally have the fault memory read out, because only this log 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 1503001853, 8917048380.

How does the repair of the 89170-48550 work?

First have the fault memory read out and attach the log. Then disconnect the battery, and only after that remove the control unit. Afterwards, create a repair order online and send the unit in well packed.

Only remove the control unit from the vehicle once the battery is disconnected, and pack it carefully afterwards.

At Airbag24, the unit is examined on the test bench, and defective components are replaced by Airbag24. The stored crash data is also deleted at Airbag24 before the function test follows. Processing usually takes 3–4 working days, after which your own unit is returned to you. 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 89170-48550 get to Airbag24?

Either you send the unit yourself as a parcel, or you book a UPS collection for an extra charge. The return shipment after the repair is made by UPS.

Shock-resistant packaging and the printed repair order in the parcel are part of the submission.