Airbag control unit with part number 89170-48640

What does the airbag control unit 89170-48640 do?

The airbag control unit 89170-48640 is the control unit of the restraint system (SRS) for Lexus. It reads the sensors for impact and deceleration, determines in an accident which airbags and seatbelt pretensioners are triggered, and monitors the system constantly for faults.

The unit stores any faults it finds and indicates them via the airbag warning light. The light in the instrument cluster is therefore the first sign that something is wrong in the system.

After an accident the unit stores crash data and locks itself afterwards. The lock is part of the protective function of the system; it is not a sign of additional damage.

Why does the control unit 89170-48640 fail?

The most common cause is crash data that was stored after an accident, even without an airbag being triggered. Normal diagnostic tools cannot erase this data. Further possible causes are:

Several causes may come into question, which relate to the age and the environment of the unit.

• aged electronic components on the circuit board
• cold solder joints that give way under load
• moisture and corrosion at the plug connections
• voltage spikes, for example from a weak battery or a jump start

Which of these causes is present only becomes clear from reading the fault memory and checking the unit. A guess alone is not enough for that.

How can you tell that the 89170-48640 is defective?

The airbag warning light in the instrument cluster stays on permanently or intermittently, and a fault message appears in the display. The diagnostic tool does not find the control unit, or the fault memory cannot be cleared.

The warning light is the signal you are most likely to notice. It shows that the restraint system has detected a fault, and you should take this indication seriously.

If airbags and seatbelt pretensioners are affected, they may not trigger in an emergency. For this reason too, you should have the cause clarified without delay.

Which vehicles is the 89170-48640 fitted in?

The unit is fitted in the vehicles named below. The airbag control unit 89170-48640 is fitted in these vehicles: Lexus RX AL10 Facelift (2012-2015) and AL10 (2009-2012).

The list below shows the vehicles that we have recorded for this part number.

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

If the part number on the label of your removed unit matches this page, you have the right unit. The comparison shows nothing more. Therefore have the fault memory read out before removal, because only the log shows whether the control unit is actually defective or whether a connector is the cause.

For the same vehicles, we also repair control units with the part numbers 1503001853, 8917048380.

How does the repair of the 89170-48640 work?

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

Airbag24 checks the control unit on the test bench, repairs defective components, erases the stored crash data and carries out a functional test. After that the unit goes back to you.

Processing at Airbag24 usually takes 3–4 working days. This time covers only checking, repairing and testing. 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 89170-48640 get to Airbag24?

You send the unit in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back to you by UPS.

Put the printed repair order in the parcel and pack the unit shock-proof.