Airbag control unit with part number 89170-53490

What does the airbag control unit 89170-53490 do?

In Lexus, the airbag control unit 89170-53490 evaluates the crash sensors. Within milliseconds it determines which airbags and seatbelt pretensioners trigger in an accident, and it monitors the system in continuous operation. Detected faults appear on the airbag warning light.

The sensors supply measured values, which the control unit evaluates continuously. It also checks whether the connected components are working correctly, so that it can react reliably in an emergency.

After an accident, the unit stores crash data and locks itself.

Why does the control unit 89170-53490 fail?

The most common cause is crash data stored after an accident, even without a triggered airbag; a normal diagnostic tool cannot delete it. Other causes that come into consideration are aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes, for example from a weak battery or jump-starting.

Crash data remains in the unit even when the airbags do not fire. Nothing can be seen of it from the outside.

The other causes grow with the service life of the vehicle. Solder joints fatigue, moisture attacks the contacts, and voltage spikes stress the circuits.

How can you tell that the 89170-53490 is defective?

If the airbag warning light in the instrument cluster stays on permanently or only intermittently, accompanied by an error message, this indicates a problem. If, in addition, the connection to the diagnostic tool fails or the fault memory remains, this points to a defect. Airbags and seatbelt pretensioners may then possibly fail to trigger in an emergency.

When the ignition is switched on, the light runs a short self-test. If it does not go out afterwards, have the finding checked.

The error message in the display shows that the system is disturbed. As long as it stays, checking the fault memory is the next sensible step.

Which vehicles is the 89170-53490 fitted in?

At Lexus, the control unit 89170-53490 was installed in these vehicles: Lexus IS XE20 (2005-2009) and XE20 Facelift (2010-2013). The list is for orientation and can be matched against the part number.

The list below shows the vehicles for which the unit is recorded in our database.

• Lexus IS XE20 (2005-2009)
• Lexus IS XE20 Facelift (2010-2013)

Have the fault memory read out before removal; the log shows whether the control unit itself is defective or whether a plug or cable is the cause. The label comparison with this page is an additional step; it only confirms the correct unit and does not clarify the cause.

For the same vehicles, we also repair control units with the part numbers 89170-53110.

How does the repair of the 89170-53490 work?

Have the fault memory read out, then disconnect the battery and remove the control unit; attach the log to the unit. Afterwards, create the repair order online and send the unit off well packed. For checking, repair and function test, Airbag24 usually allows 3–4 working days.

At Airbag24, the control unit is checked first, and then defective components are repaired. The stored crash data is deleted, followed by a function test, after which your own unit is returned to you.

The sequence in the vehicle must be observed for safety reasons. 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 89170-53490 get to Airbag24?

The control unit reaches Airbag24 as a parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 sends the repaired control unit back to you by UPS.

The printed repair order goes into the parcel, and the unit is packed so that it withstands knocks.