Airbag control unit with part number P8635A239

What does the airbag control unit P8635A239 do?

The airbag control unit P8635A239 is the central control unit of the restraint system (SRS) in Mitsubishi. It evaluates the crash sensors and determines in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered.

It also monitors the entire system continuously and reports faults via the airbag warning light.

If an accident has occurred, the unit stores crash data and locks itself. The lock is lifted only by the repair.

Why does the control unit P8635A239 fail?

The most common cause in the P8635A239 is crash data stored after an accident, even without an airbag having deployed. A normal diagnostic tool cannot erase this data. In addition, aged components, cold solder joints, moisture and corrosion, and voltage spikes come into consideration.

As long as the crash data remains in the memory, the control unit continues to show the fault, even if the rest of the electronics work perfectly.

The other causes concern the components inside the unit and the plug connections. Aged components and cold solder joints impair function, while moisture and corrosion disrupt electrical contact. Voltage spikes arise, for example, when the battery is weak or a jump start is connected.

How can you tell that the P8635A239 is defective?

The airbag warning light in the instrument cluster shows a defect in the P8635A239 by lighting up permanently or intermittently. Added to this are a fault message in the instrument cluster, a missing connection to the diagnostic tool, and a fault memory that cannot be cleared.

With such a finding it is especially important that airbags and seatbelt pretensioners may not deploy in an emergency. This also applies if the vehicle seems inconspicuous in everyday use.

Do not dismiss the indication as a minor matter; have it checked promptly.

Which vehicles is the P8635A239 fitted in?

The assignment applies to Mitsubishi. The airbag control unit P8635A239 is fitted in these vehicles: Mitsubishi Lancer CY (2007-2017).

Here is an overview of the models:

• Mitsubishi Lancer CY (2007-2017)

Comparing the part number on the label with this page only confirms that you have the correct unit. Whether a defect exists is shown only by reading out the fault memory, which you should have done before removal. A plug or a cable can just as well be the cause.

For the same vehicles, we also repair control units with the part numbers P8635A146, P8635A168, TARME1308R0924, TARME2937R0152.

How does the repair of the P8635A239 work?

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

Pack the removed unit well and send it in. The sequence protects you during work on the restraint system.

Airbag24 checks the unit on the test bench, replaces defective components, erases the crash data and carries out a function test. Then your own unit goes back 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 P8635A239 get to Airbag24?

You send the control unit P8635A239 to Airbag24 as a parcel, or you book a UPS collection for an extra charge. After the repair Airbag24 sends it back by UPS.

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