Electrics Gone Haywire

[graemew81]

Hi All,
Apologies for the long post but wanted to get all the detail included.
I‘be had my E320 W211 Estate (2006 facelift) for just over 2 weeks. We’ve covered nearly 1k miles together without issue in all sorts of weather.
This morning I took it to the local car wash (the type with rollers) and a few minutes after leaving, the headlamp washes turned themselves on and didn’t stop, even when there was no more water left.
I got the extra half a mile home and turned off the engine, the washers were still pumping out nothing and then the horn started (continuously) for about another 2 minutes, then all went quiet.
I put my key in the ignition, got ESP and SRS warnings and the key would of turn at all.
I plugged in my cheapo OBD plug and got a number of codes (see attachment).
A few hours later, I disconnected the battery for 30 minutes and then reconnected. The car now starts, SRS and ESP have gone but still have same fault codes on the OBD, as well as the expected engine warning light. Any ideas?
I‘m not sure if the car wash was just a coincidence, I’ve driven for a few hours in some horrendous rain recently with no issues. I’ve also checked all fuse box areas and the battery and there are no signs of water ingress.

Cheers
Graeme

 

[V6Matty]

That sounds like something has got flooded during the wash, check the fuse boxes and then engine ECU for water. Likelihood is that the screen drains are blocked and the waters escaping into the footwells and playing havoc

 

[Cole@MBS]

Check the front drivers side fuse box for water, that’s the one that powers all the said items you have wrong!

 

[mioba]

The attachment looks like a rain overview. Seems some water has got in the car.

Pop the bonnet, get a vacuum in the all the scuttles and make sure no leaf debris in there. Clean the drains.

Leave the bonnet open and let things dry out esp fuse box. Use a hairdyer.

Invest in a code reader that lets you clear error codes.

Make sure the sealing rubbers in the engine bay are complete and intact.

Take it from there and report back.

 

[graemew81]

Thanks everyone. Great advice as always. I’ll try all that tomorrow and feedback

 

[daibevan]

I had loads of random electrical faults when my front fuse box got a soaking. Carried on for days.
I removed all fuses & relays, dried it thoroughly with a hair dryer several times & finally gave it a good spraying with ACF50.
For 3 days I had to disconnect the battery at night as the horn would start sounding, the lights would come on &/or the fan would come on & run fast & loud.
I thought I was done for.
Eventually all came good.
I now regularly clean all my drains, even though that wasn't the cause, it was a flash storm when I had the fuse box cover off so I could reach the bulkhead to fix a leak into the cabin at the bonnet release cable grommet.

 

[Frontstep]

Water and electrics often fall out and sulk for days.

Don't squirt oily stuff in as it can "dam up" the moisture trapping it in.

 

[00slk]

After my s211 has a wash or it rains heavily the parking sensors have a little hissy fit

 

[daibevan]

I used the ACF 50 after all was dry to try and keep any possible rust at bay.

 

[Frontstep]

I used the ACF 50 after all was dry to try and keep any possible rust at bay.

Your right I wasn't clear that I meant it needs to be dry first, then it is good stuff to prevent corrosion as you say.

Better to do it before you need it to save the problems.

 

[Doug1234]

After my s211 has a wash or it rains heavily the parking sensors have a little hissy fit

I have had this on my Jeep ( its the only vehicle I have ever had with parking sensors !!! )
Anyway dry the sensors or wait until weathers dry and they have shut up randomly screaming and then spray them with silicone and wipe excess off , you can apparently use wd40 but I know that can give certain types of rubber a hard time so use silicone instead.
Did this about 4 months ago and they have behaved ever since.
Lots of videos on Youtube etc.

 

[graemew81]

All sorted. I guess the car had time (and a sunny day yesterday and today) to dry everything out. Just one error code this morning when I reconnected the battery and I was able to clear that via OBDII.
The drain channels were badly clogged so cleaned them out and will keep an eye on them in the future.
Thanks for the great advice everyone