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Discussion Starter #1
I wonder has anyone had this one yet.

I bought a second hand Leaf which had sustained a bang on the back. The Airbag light is on since the day I got it. Got the codes read. B1425 appeared which tells me that I had a rear collision. Thank goodness for technology - I wouldn't have known only for it! I don't think any of the airbags have deployed and the rear collision would kind of follow.

Anyway, I'm trying to get the codes cleared from the Airbag Module behind the direction selector between the front seats. It's 98820 3NL0A. I brought it to the man who can clear all but he failed as of yesterday but is confident that another swing at it will get it clear. He has rewritten the ROM in the module, but the same error code keeps reappearing.

2 questions
1. Any suggestions on the above?
2. What triggers the code? I've seen the circuit board and there's nothing there that has g-force detection, I would say. But I wonder if some device has triggered the code and is possibly still set.

I'll report back on the second visit to "the man"
 

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I wonder has anyone had this one yet.

I bought a second hand Leaf which had sustained a bang on the back. The Airbag light is on since the day I got it. Got the codes read. B1425 appeared which tells me that I had a rear collision. Thank goodness for technology - I wouldn't have known only for it! I don't think any of the airbags have deployed and the rear collision would kind of follow.

Anyway, I'm trying to get the codes cleared from the Airbag Module behind the direction selector between the front seats. It's 98820 3NL0A. I brought it to the man who can clear all but he failed as of yesterday but is confident that another swing at it will get it clear. He has rewritten the ROM in the module, but the same error code keeps reappearing.

2 questions
1. Any suggestions on the above?
2. What triggers the code? I've seen the circuit board and there's nothing there that has g-force detection, I would say. But I wonder if some device has triggered the code and is possibly still set.

I'll report back on the second visit to "the man"
I am not 100% sure on Nissan airbag ecu, but having worked in IT in the automotive industry for many years if an airbag ecu / g sensor has been triggerd the whole module has to be replaced, did the seat belt pretensioners fire?

You will find many people who offer to repair and reprogram the eprom in an airbag ecu, however the manufacturer only rates them for one impact and then need to be replaced.

I don't know about you but I don't like the thought of an ecu getting bodged and not firing when I need it most.
 

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Discussion Starter #3
I am not 100% sure on Nissan airbag ecu, but having worked in IT in the automotive industry for many years if an airbag ecu / g sensor has been triggerd the whole module has to be replaced, did the seat belt pretensioners fire?
Update

Yes Spudnet - looks like you are right. I went "the man". First he said an hour, then another hour and then another day. So after the day, he said he had it fixed and it was by replacing with another module. Problem here was that even though it was from a Leaf, the EV error light was showing after the replacement. And when he read the codes with this light on, it came back with no error codes. He said it said something about CAN bus error. Anyway, I decided to go back to the original module and just the airbag light. I don't think the pretensioners fired. Given that it was a rear end bang as indicated correctly by the error code, I wouldn't have expected them to fire.

You will find many people who offer to repair and reprogram the eprom in an airbag ecu, however the manufacturer only rates them for one impact and then need to be replaced.

I don't know about you but I don't like the thought of an ecu getting bodged and not firing when I need it most.
The fact that he couldn't rewrite the ROM or clear the codes did surprise me. The triggering must take place in the module itself. In one of the chips??? I doubt it. Are there G-force sensors in all directions so the front bag will deploy in the event of a frontal and side bags after a side bag etc. Again I'm doubtful. (this is why my wife loves me!!!) I definitely think the main two front bags at least have internal triggers.

I wouldn't be too worried about reusing a module. Everything is repairable. But what do you repair??

Another question. Why do you see airbag modules for sale with crash data? Why would anyone buy one if the device is physically damaged?

If I have to buy a new module it'll cost more than the car, I suspect.
 

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Discussion Starter #4
Update. I took my original module apart and see that it had been opened already and the EEPROM removed and returned, I would say. I don't know if my man did it or was it done before but I'd guess it was my man.

According to other forums, the EEPROM is a 95128 from ST. There are a number of variants of this chip one of which has a read only setting which means that further writing can be disabled. I wonder if this is the variant in the Airbag module and this is the reason why the module would be deemed defunct after a collision and would need to be replaced. If so, it might be possible to replace the read only device with another read only or a non read only one either of which is written with the correct BIN file. Anyway, that's where it stands.
 
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