Electrical problem?

Tiny
KEVINP595
  • MEMBER
  • 2010 AUDI A3
  • 1.9L
  • 2WD
  • MANUAL
  • 19,000 MILES
Hey, I have an Audi a3 8p with some problems.
First both number plate lights went off.
Then a couple days later, when I put the car in ignition, the motor fan went full speed, headlights wouldn't turn off or change to DRL and obd2 port won't work, so I can't scan the issue.
I have checked all fuses in motor space and inside cabin.
And the car battery is kind of new and strong. I have tried to do an ECU reset but that did not work either. What should I do next? Thanks for all answers.
Friday, January 13th, 2023 AT 8:16 AM

10 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,269 POSTS
Hi,

I need clarification on the engine. I attached a pic below showing the engine indicated in my manual. It's not showing a 1.9L.

Let me know which you have.

When you checked the fuses, it is also important to check that there is power to and from them. You could have a good fuse not getting power. I can go through wiring schematics once I determine the engine.

Take a look at this link:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know.

Joe

See pic below.
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Friday, January 13th, 2023 AT 9:28 PM
Tiny
KEVINP595
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Hey, my engine is 1.9 TDI. Thanks for the video. I got a fuse checker and checked the fuses that control the light and such. The fuses are new and working, but the fuse checker did not light up on the fuses I made a little red circle in the picture, those are the ones that controls light and other things. The rest of the fuses in the picture outside the red circle light up when checking with the fuse checker and seems to be working correctly. So, it has to be something behind the whole fuse box or something that is wrong? Perhaps some relay?
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Saturday, January 14th, 2023 AT 8:59 AM
Tiny
KEVINP595
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  • 7 POSTS
Same with the fuses in the motor space. Here is a pic. All working fuses, but some get no power like you said.
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Saturday, January 14th, 2023 AT 9:11 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,269 POSTS
Hi,

It could be from behind the fuse box or there could be one of them that powers others that may have failed.

I tried looking through the wiring schematics for a 2.0 Diesel hoping I could narrow it down, but I can pinpoint the fuses you circled. By any chance, do you have the fuse numbers in the box or specifically what they power?

Let me know.

Joe
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Saturday, January 14th, 2023 AT 8:49 PM
Tiny
KEVINP595
  • MEMBER
  • 7 POSTS
The 4 fuses that is not working in the cabin does.

1 Engine components (I), manual headlight beam adjustment, automatic headlight beam adjustment, AFS control module, engine components (II), light switch (switch lighting/illumination), diagnosis socket 10
2 All Wheel Drive, automatic transmission, control module for CAN data transfer (gateway), electromechanical steering, shift gate automatic transmission, engine relay, fuel tank control unit, engine control unit, brakes control (ABS), Eleclltronic Stabilization Program (ESP), Anti-Slip Regulation (ASRl, brake light switch 10
3 Airbag 5
4 Air-conditioning (pressure sensor, air quality sensor), button for Electronic Stabilization Program (ESP), Anti-Slip Regulation (ASRI, oil level sensor (WIVl, back-up light switch, front seat heating, Seat-occupancy recognition (on USA vehicles), navigation, garage door opener, automatic mirror dimming, Heated windshield washer nozzles, air conditioning (control module 5
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Sunday, January 15th, 2023 AT 11:45 AM
Tiny
KEVINP595
  • MEMBER
  • 7 POSTS
In the engine. The fuses that are not working:

F13 Engine control module
F14 Ignition coils
F15 Tank diagnosis, oxygen sensor

F21 Oxygen sensor
F22 Clutch pedal switch, brake light switch
F23 Engine relays, engine components
F24 Engine components
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Sunday, January 15th, 2023 AT 11:56 AM
Tiny
KEVINP595
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And I noticed also in the cabin that two more fuses did not work.

40 Heating (blower fan) 40
41 Rear window wiper 15
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Sunday, January 15th, 2023 AT 12:12 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,269 POSTS
Hi,

Wow, that is a lot of them not working. Keep in mind, what I have isn't for the 1.9L engine. But most of the fuses you mentioned crossed.

So here is what I recommend testing or checking. There are four power control relays in the under-hood relay box. In this case, it appears that power control relay (30 B+) is what powers the fuses you mentioned.

So, remove the relay and check the connectors in the box and on the relay.

Here is a link that explains how to test a relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Hang in there. We'll figure it out.

Take care,

Joe

See pics below.
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Sunday, January 15th, 2023 AT 6:23 PM
Tiny
KEVINP595
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Problem solved! I made 1 rookie mistake in the beginning. I didn't check the fuses with the car on. So, all fuses did work. I checked all relays with a multimeter, and everything seems fine. So, the last thing we did was a dashboard computer reboot, to force reboot the whole computer too factory, after that everything worked! Thanks. I hope it helps with some1 else if same problem.
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Tuesday, January 31st, 2023 AT 1:52 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,269 POSTS
Hi,

Thank you for the update. That is a very easy mistake to make. Trust me, it happens to all of us.

Regardless, I'm glad to know you got it going, and thanks for the info. I know it will help others in the future.

Take care and feel free to come back anytime.

Joe
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Tuesday, January 31st, 2023 AT 5:39 PM

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