i have a 2005 e60. i have a problem with the restraint system fault.

the 3 codes from the computer i am getting are:

93fc - undervoltage
9b01 - battery isolation
9aff - firing circuit

i have cleared the codes but soon has you restart car they come back.

can any one help please

 

How old is your battery? Have the battery checked and changed if necessary.

 

Could be battery itself, charging system or the BST (battery safety terminal). Has the car had any impacts recently? Could be the BST. See this video:
2005 BMW 525i - Code 9AFF – Safety battery terminal firing circuit resistance too high - Auto-Trend Repairs and Service Information Forums

 

The battery is brand new and I have had no impacts on the car


It's getting so frustrating

 

If the battery is new, that means that the battery cables have been recently unbolted from the battery. Maybe they didn't get tightened correctly? Maybe the BST is somehow loose internally (see that video)? I'd start by looking at the battery connections and making sure nothing looks odd.

I think there is also a little signal cable coming off the BST. Maybe that is part of the sensing circuit. Is that connected?

 

I've had the 9aff - firing circuit error since September.. It has been driving me crazy. I was about to buy the new BST power cable but felt my current one looks fine so I checked it thoroughly..This is after I took it to numerous shops to clear it and it would comeback immediately after restarting the car. This morning i looked at all the battery connections and they were tight but there is a little black connection that comes from the BST positive cable I disconnected it resecured it firmly. When I cleared the code the airbag light went off and hasnt come back after restarting the car numerous times. I will check again when I get home from work too. The funny thing is I had my starter replace 2 or 3 weeks before I started getting the error and I know they disconnected the battery to perform the repair so they may have bumped it or something. Certain parts of these cars can be extremely sensitive. I'll post if the light comes back on.

 

BMW recall Campaign No 13V-564 Front Passenger Air Bag Seat Occupancy Sensor Mat.

 

It's the seat mat. Been using the car with the lights on for 2 years now. Apparently, that is not part of the safety inspection. Just got my car inspected today and it passed with the airbag light on. You can have the seatmat replaced based on the recall if it really bothers you. Dealer wanted to charge me 175 to diagnose it first.