I get the Passenger Restraint Fault after the car has sat in the rain.
I usually only the code "9404 front sensor wrong component". Sometimes along with that code I'll get "9403 front sensor, right".

After I clear the codes, and it hasn't rained, the fault stays away. Next rain, the fault comes back.

Has anyone experienced this? Does anyone know where the faulty sensor would be located?

 

Drains might be clogged and water could be leaking causing a short circuit.

 

Where are these drains?

Better yet, where would the front passenger restraint sensor be located?

 

Check the spare tire well in the trunk for moisture. Thats one place BMW put electronics and water will pool in the well if your sunroof drains are clogged or the gasket on trunk is bad. Not sure about specific sensors. Search on here for roof drains and you will find a lot of info.

 

In the link below you have the sensor ending in 1595 (old one)

RealOEM.com - Part Search

I wen thru the same issue awhile ago and had to replace the two front crash sensors under the bumper, dealer wanted $1200 did it myself for less than $100 hardest part was removing front bumper OTT. Easy easy....
Suspect you had software updated by dealer recently and new SW Is incompatible with older sensors stupid BMW. I know but it is what it is.
Get two of the newer used sensors off eBay (get the newer part ending in 4608 part number) like I did and problem solved.
Just remember to disconnect your battery, no coding required OT DELETING OLD fault codes
I did a wrteup on this somewhere about a year ago.
Have fun.

This may help also:https://5series.net/forums/diy-do-yo...l-tips-140649/

 

Next time it rains I'll will check for water/moisture in the spare tire well. If all is dry, I will do the front crash sensor swap. Considering the codes 9403 & 9404, my guess it will end up being the sensors.

CMYACHTIE, I've read some of your past posts on this subject where you suspected water intrusion. Do you think the sensors behind the front bumper are getting wet?

Thanks all

Deano

 

They are exposed enough to they will get wet in their position, as they are behind the grill.

Strangely though at first I only had a problem when car was parked in the rain never a problem driving in rain and really cannot imagine that they would get wet unless driving in the rain and water is forced into the kidney grills so I suspect that all it was really a bad connection/ground with the sensors. I did get the new grounding (mounting)straps from the dealer so all connections are now as good as new again.

 

Get the codes read. Mine was the "UpFront Sensor Left" (The crash sensor in the front bumper). BMW calls it the "accelerating sensor" in the parts fische.