Airbag control unit with part number 89170-50L52

What does the airbag control unit 89170-50L52 do?

The airbag control unit 89170-50L52 coordinates the restraint system (SRS) in Lexus. It processes the measured values of the crash sensors and decides in an accident within milliseconds which airbags and seatbelt pretensioners are triggered.

In operation it checks the entire system continuously and reports faults via the airbag warning light. After an accident the unit stores crash data and then locks itself.

The interplay of sensors, control unit and triggering system forms the basis of the protective function.

Why does the control unit 89170-50L52 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 include aged electronic components, cold solder joints, moisture or corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

Crash data are records that the unit creates after an accident. The other causes can only be narrowed down with the read-out fault memory.

A plug connector with moisture can cause contact problems without the control unit itself being affected. Such cases can be told apart only by a precise check.

How can you tell that the 89170-50L52 is defective?

A defect shows first on the airbag warning light in the instrument cluster. If the diagnostic tool cannot establish a connection or the fault memory cannot be cleared, that is a clear indication.

Typical signs are:

• The airbag warning light stays on permanently or intermittently.
• A fault message appears in the instrument cluster.
• The diagnostic tool gets no connection to the control unit.
• The fault memory cannot be cleared.

If these signs occur, airbags and seatbelt pretensioners may fail to trigger in an emergency. A prompt check is therefore advisable.

Which vehicles is the 89170-50L52 fitted in?

The 89170-50L52 is fitted in the following vehicles: Lexus LS XF50 (from 2018).

The listing below sets out the vehicles.

• Lexus LS XF50 (from 2018)

Compare the part number on the label of the removed unit with this page, so you can be sure you have the right unit. Have the fault memory read out beforehand as well, since only it shows whether the control unit is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 89170-50K81, 89170-50K83, 89170-50L00, 89170-50L03, 89170-53790, 89170-53820.

How does the repair of the 89170-50L52 work?

First have the fault memory read out and enclose the log. Then disconnect the battery, remove the control unit and create the repair order online. Processing at Airbag24 usually takes 3–4 working days.

The sequence is mandatory, because the control unit may only be removed after the battery has been disconnected. Then send the well-packed unit.

Airbag24 tests the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. Then 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 89170-50L52 get to Airbag24?

You send the unit as a parcel, or for an extra charge you have it collected by UPS. After the repair it is sent back to you by UPS.

Include the printed repair order in the parcel and pack the control unit shockproof.