Airbag control unit with part number EH14-57K30-C

What does the airbag control unit EH14-57K30-C do?

The airbag control unit EH14-57K30-C is the central control unit of the restraint system (SRS) for Mazda. It evaluates the signals from the crash sensors and decides within milliseconds in a crash which airbags and seatbelt pretensioners are triggered.

During operation, it monitors the system continuously. Faults found are indicated via the airbag warning light in the instrument cluster.

After a crash, the unit stores crash data and then locks itself.

Why does the control unit EH14-57K30-C fail?

In the EH14-57K30-C, the most common cause after an accident is stored crash data, even if no airbag has deployed. Other causes are ageing components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data cannot be erased with a standard diagnostic tool. Airbag24 erases it during the repair.

Ageing electronics and cold solder joints lead to unreliable contacts. Moisture and corrosion at plug connections disturb signal transmission.

Voltage spikes, for example from a weak battery or a jump start, put additional strain on the electronics.

How can you tell that the EH14-57K30-C is defective?

A defect in the EH14-57K30-C shows up as the airbag warning light in the instrument cluster, as an error message, as a missing connection to the diagnostic tool or as a fault memory that cannot be cleared.

The following signs indicate this:

• Airbag warning light on permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool receives no connection to the control unit
• Fault memory cannot be cleared

With such signs, airbags and seatbelt pretensioners may not trigger in an emergency. The warning light shows the fault, so a prompt check is advisable.

Which vehicles is the EH14-57K30-C fitted in?

The EH14-57K30-C is fitted in these vehicles: Mazda CX-7 ER (2006-2009) and ER Facelift (2009-2012).

The following list shows the vehicles stored for this part number.

• Mazda CX-7 ER (2006-2009)
• Mazda CX-7 ER Facelift (2009-2012)

Compare the part number on the label of the removed unit with this page. This only ensures that it is the right unit.

Have the fault memory read out beforehand, because only this result 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 0J14A3906642, 9H05A3906641.

How does the repair of the EH14-57K30-C work?

First, read out the fault memory and enclose the printout. Then disconnect the battery and only then remove the EH14-57K30-C. Next, create a repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days.

On the test bench, Airbag24 checks the unit, replaces the defective parts, removes the crash data and tests the function. Afterwards, your unit goes back to you.

The 3–4 working days refer only to testing, repairing and checking at Airbag24. Reading out, removal and shipping are not included.

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 EH14-57K30-C get to Airbag24?

You send the control unit EH14-57K30-C as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back by UPS.

Put the printed repair order into the parcel and pack the control unit shockproof.