Airbag control unit with part number 89170-48400

What does the airbag control unit 89170-48400 do?

The airbag control unit 89170-48400 is the central control unit of the SRS for Toyota. It evaluates the crash sensors, determines in an accident within milliseconds which airbags and seatbelt pretensioners to trigger, and monitors the system continuously.

The control unit reports faults in the system via the airbag warning light in the instrument cluster.

If the vehicle is involved in an accident, the unit stores crash data and locks itself. Only a repair lifts this lock.

Why does the control unit 89170-48400 fail?

On the control unit 89170-48400, the most common cause after an accident is stored crash data, even if no airbag has deployed; a standard diagnostic tool cannot remove it. In addition there are ageing electronics, cold solder joints, corrosion at plug connections, moisture and voltage spikes.

Crash data is the trace of an accident in the unit's memory. Whether an airbag was triggered makes no difference to the entry.

The other causes lie in the electronics and their connections. Ageing components, cold solder joints, and moisture and corrosion at plug connections can cause faults.

Voltage spikes, for example from a weak battery or a jump start, also belong to the causes.

How can you tell that the 89170-48400 is defective?

A defect in the control unit 89170-48400 shows itself through the airbag warning light, fault messages in the instrument cluster, a diagnostic tool without a connection to the control unit, or a fault memory that cannot be cleared.

Typical signs are:

• Airbag warning light in the instrument cluster lights up constantly or intermittently
• Fault message in the instrument cluster
• Diagnostic tool cannot establish a connection to the control unit
• Fault memory cannot be cleared

Airbags and seatbelt pretensioners may then fail to deploy in an emergency. Therefore have the finding checked.

Which vehicles is the 89170-48400 fitted in?

The control unit 89170-48400 is fitted in these vehicles: Toyota Highlander XU40 (2007-2013).

The overview shows the vehicles for which the unit is intended:

• Toyota Highlander XU40 (2007-2013)

Compare the part number on the label of the removed unit with this page to make sure you have the correct unit. Read out the fault memory in advance, because only the log 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 89170-48090, 89170-48240.

How does the repair of the 89170-48400 work?

Processing at Airbag24 usually takes 3–4 working days. Airbag24 checks the control unit 89170-48400 on the test bench, repairs defective components, deletes the crash data and carries out a function test.

Before removal you have the fault memory read out and enclose the log with the unit. Then disconnect the battery; only afterwards remove the control unit.

Then create a repair order online and send the unit in well packed. After the repair you receive your own unit back.

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 89170-48400 get to Airbag24?

You send the control unit 89170-48400 in as a parcel or book a UPS collection for an extra charge. Airbag24 returns it by UPS after the repair.

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