Airbag control unit with part number 89170-30540

What does the airbag control unit 89170-30540 do?

The airbag control unit 89170-30540 is the central control unit of the restraint system (SRS) for Lexus. It processes the signals of the crash sensors, triggers the appropriate airbags and seatbelt pretensioners within milliseconds in the event of an accident, and monitors the system continuously. After an accident, it stores crash data and locks itself.

The unit reports faults via the airbag warning light in the instrument cluster. This way you notice faults without having to check the system yourself.

Why does the control unit 89170-30540 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered; a normal diagnostic tool cannot erase it. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or jump start.

Crash data remains in the memory of the control unit, even if no seatbelt pretensioner was fired on the vehicle. A diagnostic tool of the usual kind cannot reach it.

Aged components and cold solder joints lead to contact problems that appear only irregularly. That is why the fault is hard to narrow down without reading out the memory.

Moisture and corrosion at plug connections worsen the contact, and voltage spikes stress the electronics additionally.

How can you tell that the 89170-30540 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently. An accompanying fault message appears, the diagnostic tool cannot reach the control unit, and the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The warning light is the clearest warning signal you get. In this case, have the fault memory read out promptly.

A missing connection to the diagnostic tool can also be caused by a cable or a plug. Only the memory shows where the cause lies.

Which vehicles is the 89170-30540 fitted in?

The control unit 89170-30540 is fitted in these vehicles: Lexus GS S190 Facelift (2009-2011) and S190 (2005-2009).

The list of vehicles we have on record for this part number follows.

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

Compare the part number on the label of your removed unit with this page, so that you have the correct unit in front of you. Whether the control unit itself is the cause is only clarified by the fault memory read out beforehand, because it shows whether a plug or a cable is affected.

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

How does the repair of the 89170-30540 work?

Have the fault memory read out and attach the log, then disconnect the battery and only then remove the control unit. Afterwards create a repair order online and send in the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

On the test bench, Airbag24 examines the control unit, replaces defective components, erases the stored crash data and carries out a function test.

Afterwards the unit goes back 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 89170-30540 get to Airbag24?

You send the unit as a parcel or arrange a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

The printed repair order goes into the parcel, and the unit is packed shock-proof.