Hi guys I have a weird problem.

When I drive the car for about 20-25mins it blows number 43 - which points to engine management.
It's strange that it doesn't blown straight, but after some time driving and it drives me crazy.
Any suggestions on how to fix it?
 

That's going to take a bit of detective work; that fuse supplies all sorts!

Charcoal filter purge valve

Secondary air pump relay coil

Secondary air inlet valve

Both lambda sensor heaters

MAF sensor.

 

 

Oh, in that case I'll have to measure those things. When I first start the car while fuse not blown yet, I hear the auxiliary heater for a minute and then stops. But when the fuse blown its like entire car shut off for a second and come back.

I wonder how can I found where exactly is the problem but guess can buy some shortcut tester and try with it.

 

Thanks 🙏 

 

I guess you can just unplug each of those things, one at a time, until you find one which stops the fuse blowing.

You'll generate lots of fault codes and warning lights in the process.  They'll probably all go away after a while of everything being reconnected. 

Today with a friend we opened the seconday air relay and tested it looked okay in terms of measurement.
But we also saw some dark spots on the relay box like dust left and he suspected this relay.
So we removed it and I drove the car for about 30 minutes and the fuse had not blown, guess it could be that one 
or else I need to test with the relay inserted to be sure?
On the VCDS only relay j299 was shown as not working and on the dashboard this sign for ASR was shown.
I'm planning on purchasing a new relay and see if the problem will be resolved.
Other than that car is running normally even I pushed it a little bit more and no check engine

Edited 19 June, 20241 yr by Techktonik

So I've went out in the morning to drive a little bit and without the relay again the fuse blown, but I noticed it when I started the air conditioner and few minutes later it blow it so 

will continue testing the rest parts by disconnecting one by one..
 

Charcoal filter purge valve

Secondary air inlet valve

Both lambda sensor heaters

MAF sensor.

Ok, tried dissconnecting the charcoal filter purge valve and same story
Need to check MAF sensor or most likely this secondary air inlet valve (by lambda sensor heaters I don't know never got a sign for it)
 

Pff this is strange, disconnected everything except (lambda sensors) started the car started A/C and the fuse again blown maybe I have to look for a technician

Edited 21 June, 20241 yr by Techktonik

One of the lambda sensors heaters is the most likely reason, Z19 or Z29

 

 

 

 

Edited 21 June, 20241 yr by Crasher

Ok, will check it thanks,
Do you have some schema to find where they're connect to unplug them for example could be the one on top of the engine not under the car

Unplug the one that's easiest to find the connector for, probably nearest engine.

So today I layed under the car and checked the cables for the lambda sensor, covered the good ones with insulation tape and the rest two as well separately. The best solution might be to cut off the cable and re-solder it, but anyway it fixed my problem. Despite the fact that it was a little struggle, connecting disconnecting I also cleaned some cable plugs with contact cleaner in the meantime.

 

So I wanna thank you guys for your help appreciate it  @Breezy_Pete @Crasher

🙏 🙂 

The wire used in Lambda sensors is very difficult to solder and solder is not a good idea anyway, best to replace the sensor.