Help Needed – SRS Airbag Fault (B00012A) Still Not Fixed After Replacing ECU and Using VDASH

[MarwanSUL]

Hi everyone,

I’m really hoping someone here can offer insight because I’ve tried everything I can think of, spent a fortune, and I’m still stuck with a non-functional SRS system and other VDASH-related problems.

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The Core Issue:

I’ve been trying to fix a persistent SRS airbag fault (B00012A) on my Volvo XC90 (driver’s airbag circuit range/performance). So far I’ve:
• Replaced the driver’s airbag (same part number).
• Verified the clock spring is working.
• Had the wiring professionally checked – no faults.
• Even tried using a resistor to simulate the airbag – same fault returned.

The conclusion was: maybe the SRS ECU is faulty.

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What I Tried Using VDASH:

I subscribed to VDASH and requested the PIN originally to disable the Trailer Module (TRM) — but that also failed, even after unlocking with the correct PIN.

Then I moved on to SRS configuration using VDASH:

Equipment:
• Started with VOE Ethernet OBD, but it kept failing on key features.
• Upgraded to the Super J2534 cable (officially listed as compatible by VDASH).

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SRS ECU Configuration Attempts:
1. Original SRS ECU, Paid for ECU Configuration
• VDASH showed “configuration successful” after ~30 seconds.
• But nothing changed. Fault code B00012A still there.
2. Donor SRS ECU (same part number)
• Paid again to configure this one.
• Same story: quick “successful” message but no change.
• Airbag light started flickering, and I got a VIN mismatch + same B00012A fault.

I then reinstalled the original ECU, defeated, with no improvement.

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Other Ongoing Problems:
• I cannot restore CEM to original values — VDASH always gives a “can’t read ECM data” error.
• I cannot clone ECUs — dropdown is empty even when all hardware is connected and the car is powered properly.
• VDASH says “successful,” but it doesn’t seem to actually write or change anything.
• Feels like I’m stuck in a loop with no real progress, despite the “green lights” and power all reading correctly.

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My Questions:
• Has anyone fixed B00012A through VDASH or another method?
• Could the SRS ECU store airbag serial data, and mismatched values are causing this?
• Has anyone else gotten VIN mismatch errors when swapping a “compatible” SRS ECU?
• Why would configuration complete in seconds without any visible effect?
• What does the “can’t read ECM data” error actually mean? Could it block other functions?
• Any recommended Volvo diagnostic tools that actually work?

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If anyone’s been through something similar or can give any guidance, I’d truly appreciate it. I’ve already invested a fortune and a lot of time — I just want to get the car working safely again.

Thanks in advance,
Marwan