Washed my car and now it won't start (electronics)

TrustyDelux

New Member
Hi folks,

I have a 2006 B7 Cabriolet 1.8T. Yesterday afternoon I washed the car with my pressure washer and since doing so none of the electronics on the car work and it obviously won't start.

If I put the key in the ignition and turn I get nothing. No lights on the dash, no buzzing or whirring. The central locking doesn't work. Even the little red flashing light in the passenger door is off. The battery is only one month old.

I've checked the fuses in the side of the dash and none of them are blown. I tried to jump start the car, but also nothing changed. Dead as a dodo.

Is it possible that I've managed to get water somewhere nasty and it's done something terrible?

When it comes to car electronics I'm completely out of my depth. I'm not sure where to go to begin diagnosing this problem. Any help is much appreciated!
 

Robbyb

Registered User
Hi folks,

I have a 2006 B7 Cabriolet 1.8T. Yesterday afternoon I washed the car with my pressure washer and since doing so none of the electronics on the car work and it obviously won't start.

If I put the key in the ignition and turn I get nothing. No lights on the dash, no buzzing or whirring. The central locking doesn't work. Even the little red flashing light in the passenger door is off. The battery is only one month old.

I've checked the fuses in the side of the dash and none of them are blown. I tried to jump start the car, but also nothing changed. Dead as a dodo.

Is it possible that I've managed to get water somewhere nasty and it's done something terrible?

When it comes to car electronics I'm completely out of my depth. I'm not sure where to go to begin diagnosing this problem. Any help is much appreciated!

Ok this is what I’d do.

1. Check battery
2. Find ecu and check it’s ok
3. Check both fuse boxes. Engine and in dashboard.

To me it sounds like the ecu is water damaged.


Sent from my iPhone using Tapatalk
 

Robbyb

Registered User
Hi folks,

I have a 2006 B7 Cabriolet 1.8T. Yesterday afternoon I washed the car with my pressure washer and since doing so none of the electronics on the car work and it obviously won't start.

If I put the key in the ignition and turn I get nothing. No lights on the dash, no buzzing or whirring. The central locking doesn't work. Even the little red flashing light in the passenger door is off. The battery is only one month old.

I've checked the fuses in the side of the dash and none of them are blown. I tried to jump start the car, but also nothing changed. Dead as a dodo.

Is it possible that I've managed to get water somewhere nasty and it's done something terrible?

When it comes to car electronics I'm completely out of my depth. I'm not sure where to go to begin diagnosing this problem. Any help is much appreciated!



Sent from my iPhone using Tapatalk
 

TrustyDelux

New Member
Ok this is what I’d do.

1. Check battery
2. Find ecu and check it’s ok
3. Check both fuse boxes. Engine and in dashboard.

To me it sounds like the ecu is water damaged.


Sent from my iPhone using Tapatalk
Thanks for this.

Is the ecu not in a weatherproof box? I didn't wash the engine bay, so just wondering how likely it is that water got in there... Watching that video it's not the simplest of jobs.
 

Robbyb

Registered User
Thanks for this.

Is the ecu not in a weatherproof box? I didn't wash the engine bay, so just wondering how likely it is that water got in there... Watching that video it's not the simplest of jobs.

Yes they are but like anything, seals degrade, I’d be having a look at that first. It would explain why it’s not doing anything. Are all the relays ok?


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TrustyDelux

New Member
Yes they are but like anything, seals degrade, I’d be having a look at that first. It would explain why it’s not doing anything. Are all the relays ok?


Sent from my iPhone using Tapatalk
Gotcha. Well, I just checked the area around the ecu (didn't open it up) and it's bone dry. There's quite a few leaves and in that area, so considering I only washed it yesterday afternoon I'd expect that area and leaves to be at least damp.

I'm going to check the relays. I watched a YouTube video and it looks as though it's just the ones under the steering wheel?

A couple more YT vids and I'm sure I'll work out how to test the relays.
 

mikep99

Registered User
if nothing at all is working, I'd be checking the battery and connections to start with and go from there.
It's possible something has drained it while you've been washing it.
Have you put a multimeter on it to check the voltage?

Mike
 

TrustyDelux

New Member
if nothing at all is working, I'd be checking the battery and connections to start with and go from there.
It's possible something has drained it while you've been washing it.
Have you put a multimeter on it to check the voltage?

Mike
I'll dig my multimeter out and give that a go first, Mike, thanks.
 

Donfero

Registered User
If not the battery, check for water under the driver seat. It maybe the convenience ecu.

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NHN

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VCDS Map User
I suspect as above, you've had overflow water into passenger footwell & its fried the module under passenger front footwell.
 
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