Airbag control unit with part number 89170-76140

What does the airbag control unit 89170-76140 do?

The airbag control unit 89170-76140 forms the central control unit of the SRS system for Lexus. It checks the crash sensors, determines within milliseconds after an impact which airbags and seatbelt pretensioners fire, and monitors the system continuously.

The unit stores detected faults in the fault memory and shows them via the airbag warning light. This display in the instrument cluster is the most important indication for the driver.

After an accident the control unit secures crash data and locks itself. Only a repair lifts the lock.

Why does the control unit 89170-76140 fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed; a normal diagnostic tool leaves it untouched. Further causes are:

• aged electronic components
• cold solder joints
• moisture and corrosion at plug connections
• voltage spikes

The crash data remains in the memory, and the vehicle may then appear to work perfectly. The entry is still there and affects the function of the system.

Which cause applies in an individual case can only be established by examining the unit.

How can you tell that the 89170-76140 is defective?

A defect shows up as the airbag warning light, an error message in the instrument cluster, a lost connection to the diagnostic tool and a fault memory that cannot be cleared.

• Airbag warning light lit permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool cannot find the control unit
• Fault memory cannot be cleared

In that case the airbags and seatbelt pretensioners may not deploy in an emergency.

The warning is a clear indication that should not be ignored.

Which vehicles is the 89170-76140 fitted in?

The 89170-76140 is fitted in these vehicles: Lexus CT ZWA10 (2011-2022).

The following vehicles are on record:

• Lexus CT ZWA10 (2011-2022)

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit. Having the fault memory read out shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 89170-02C30, 89170-76160, 89170-76210, 89170-76220.

How does the repair of the 89170-76140 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the unit. Next, create the repair order online and send the unit in well packed.

Keep to the order, as the control unit may only be removed after the battery has been disconnected. The log goes into the parcel with the unit.

Airbag24 checks the unit on the test bench, replaces defective components, erases the crash data and carries out a function test. Processing at Airbag24 usually takes 3–4 working days.

Your own, repaired unit is then 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 89170-76140 get to Airbag24?

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

Put the printed repair order in the parcel and pack the unit shockproof.