Airbag control unit with part number 89170-30840

What does the airbag control unit 89170-30840 do?

The airbag control unit 89170-30840 forms the central control unit of the restraint system (SRS) in Lexus. It evaluates the signals from the crash sensors, determines within milliseconds which airbags and seatbelt pretensioners trigger, and monitors the entire system continuously. After an accident it stores crash data and locks itself.

The control unit reports a fault via the airbag warning light in the instrument cluster. The signals from the sensors run constantly through the unit for this purpose.

Why does the control unit 89170-30840 fail?

The most common cause is crash data from an accident, even without an airbag deploying; a normal diagnostic tool cannot clear it. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes.

Crash data stored in the unit after an accident is the most frequent reason for a fault. What matters here is not whether an airbag deployed, since the storage happens regardless.

Ageing of the components, cold solder joints, moisture at the contacts and voltage spikes from the vehicle electrical system are additional possibilities. They can only be narrowed down during the check.

How can you tell that the 89170-30840 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, a fault message appears in the instrument cluster, the diagnostic tool gets no connection to the control unit, and the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

The warning light indicates a fault that the control unit has noticed. Whether it lights up permanently or only intermittently does not change this message.

A fault message in the instrument cluster or a diagnostic tool without a connection are further signs, and so is a fault memory that cannot be cleared. In each of these cases a check is advisable.

Which vehicles is the 89170-30840 fitted in?

The airbag control unit 89170-30840 is fitted in these vehicles: Lexus GS S190 Facelift (2009-2011) and S190 (2005-2009).

These vehicles are recorded for this part number:

• Lexus GS S190 Facelift (2009-2011)
• Lexus GS S190 (2005-2009)

Comparing the part number on the removed unit tells you whether the unit matches this page. Whether the control unit is defective is clarified only by the fault memory, which you have read out before removal; a connector or a cable can just as well be the cause.

For the same vehicles, we also repair control units with the part numbers 89170-30B30, 8917030630.

How does the repair of the 89170-30840 work?

First you read out the fault memory and attach the log. Then you disconnect the battery and only then remove the control unit. Finally, create the repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, repairs defective components and deletes the stored crash data. A function test follows, and then your own unit is sent back. For checking, repair and testing, 3–4 working days are usually planned.

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 89170-30840 get to Airbag24?

You send the unit as a parcel, or you book a UPS collection for an extra charge. After the repair, UPS brings the unit back to you.

Pack the unit shock-proof and enclose the printed repair order.