Technical Random canbus errors

[dragonsystem]

Hello I have a 2014 fiat 500L and I live in delaware ever since moving here anytime it gets foggy outside I get lots of canbus errors and earlier today it almost left me stuck at my work it throws a bunch of errors suck as esc dst hill start airbag and fuel cutoff I have Alfa obd and looking at the codes there is B1053 and U1701 earlier when the crash happened I was able to get it to start by undoing the negative for 5 minutes it kept the codes UO426 minicrypt no signal, U1701 Can line signal invalid, U1702 EPS module no signal,
U1703 no communication with instrument panel
U1706 BSM no signal
U1710 NCL no signal
U1726 sensing and diagnostic module no signal
U1732 tire pressure no signal U1736 ETM no signal
There was also B10AA the other modules climate steering avs and instrument where showing other errors but I regret not recording them if anybody can point me in a direction of either a really good mechanic or some knowledge on further diagnosis I would love it

Other things of note when it crashed my instrument cluster had every light on and dashes for my speed and temp out side same with the radio as well as saying I was empty and the engine was cold
Sometimes when it's wet out just hill start esc and dst go down where other times it's airbag and fuel cutoff when those 2 pop up my tachometer goes to 0 and the drivability goes away it shakes and I can't accelerate if I press the gas hard it sort of thuds like the vvt isn't letting air in but doesn't behave like that normally I also lose my coolant temp but keep outside air temp and fuel and speed
During the computer crash the car would crank but sounded like it wasn't getting fuel after looking up what a minicrypt is I think it's the immobilizer but it's not acting up anymore

This is all very confusing if you made it in the end thank you for your time and any insight you can give me I love this car to death but might ultimately have to sell it and hope it doesn't act up during a test drive

 

[the green vanper]

Check the ground points all over the car + battery connection. And the connections of the wire looms to ECU, BCU etc.

I don't know where are they located in the 500L, so hope that someone can point them out, but it's the first thing that comes to my mind.

 

[bugsymike]

As @the green vanper mentions, low voltage or poor battery/ earthing can throw up lots of error codes often from something small like an earth terminal.
Are you able to safely test the various earthing and 12 volt supply points at the OBD port, I have done this using a "breakout box" in the past when looking for can bus errors.
By the way is the battery fully charged/charging and the correct type for Stop/Start system?
Another point did moisture/water get in the ECU/BCM or the fuseboxes?

 

[dragonsystem]

As @the green vanper mentions, low voltage or poor battery/ earthing can throw up lots of error codes often from something small like an earth terminal.
Are you able to safely test the various earthing and 12 volt supply points at the OBD port, I have done this using a "breakout box" in the past when looking for can bus errors.
By the way is the battery fully charged/charging and the correct type for Stop/Start system?
Another point did moisture/water get in the ECU/BCM or the fuseboxes?

I know at least on my car the BCM is inside the car I do not have a start stop system and the battery is at 98 soh alternator also shows as very good
As for a breakout box what would I be looking for and on which pins it's not easy to recreate this issue as it's completely random for when it happens I've gone over month without seeing it that bam yesterday

 

[the green vanper]

The fact that the BCM is inside the car does not mean there could be no water inside It could be direct water ingress or condensed vapour.

Modern cars are packed with electronics, which is very sensible for voltage instability.

Water is a great conductor, and fog is nothing else than water.

ePER should become your best friend now to find the ground points and check them for proper contact. There as a dedicated ePER section for the ground points on the x250 Ducato, perhaps there's one also for the 500L

EDIT: the diagrams are in eLearn

 

[varesecrazy]

Hi

I would firstly fit a new Battery to Chassis to Motor Black Earth Cable, common failure..
Moisture gets inside and rots the inner strands.. You are experiencing problems in moist conditions

Next clear out the Duckbill Drains, that should help with cabin and dashboard moisture
Preserving electronics

 

[dragonsystem]

Hi

I would firstly fit a new Battery to Chassis to Motor Black Earth Cable, common failure..
Moisture gets inside and rots the inner strands.. You are experiencing problems in moist conditions

Next clear out the Duckbill Drains, that should help with cabin and dashboard moisture
Preserving electronics

In case anyone is curious about this issue for me it was caused by a bad ignition coil connector found that with the engine running if I wiggled #4 it would knock the can bus offline just long enough to cause all the codes

 

[The Panda Nut]

The oil connections on my TA panda seem weak I can conceive easily of poir contact.

I think lots of silly warnings are a sure sign of something basic. Its notgoing to have a fist full of faults, try a different battery, then as above earth points and leads, e u plug contacts. If this does not work,loose or bad plug connections or a wire broken in the harness. This may take more detective work.