4.0TDi A8 D3 boost/map sensor

[Mattbook]

I got in the beast this evening and the flow plug light was flashing, then the EML came on and Limp mode activated too

Ran a diagnostic with VCDS straight away and I got "boost sensor, implausible signal".

I know there's two map sensors (one for each turbo) but I can't seem to find them for looking in the engine bay..

Anyone know where abouts they are? Do I need to remove bumper and intercoolers for access?

Also should I just try cleaning them or get new?

Any input is appreciated!

 

[desertstorm]

Are you sure there are 2 MAP sensors ? . Looking at Partsbase it shows just one located on the passenger side intercooler. part number 30 in the diagram. I take it your engine code is an ASE.
Have you tried clearing the fault code. It appears that the MAP may be faulty as it's showing a 1.2 bar reading when the engine isn't running.
These faults can occur occasionally and when cleared don't recur again.You can't clean these sensors.

http://www.partsbase.org/audi/audi-a8-s8-quattro-a8q-eu-2005-14550-charge-air-cooler/

The part code IS 038906051B
http://www.ebay.co.uk/itm/Bosch-MAP...994810?hash=item2ed8373eba:g:S3MAAOSw6EhUP8Ef

You can get cheap MAP switches new for £11 , I would only fit a genuine Bosch part as it's a right royal pain to do and you only want to be doing it once.

Looking at Elsa Win you need to Jack the car and remove both wheels, remove the front part of the wheel liners , then remove the front bumper.
I have appended the PDF's from Elsa WIin

Karl.

 

[Mattbook]

Really appreciate that Karl, thanks a lot for the help mate.

No I'm not 100% there are two, I saw on another threat that there's one per turbo so stuck with that. Clearly though looking at the PDFs there's only one, located near side front. I'll get one ordered then and see if I can bosh it one evening when I'm home from work.

I did clear the faults and started her up again when I did the scan but the fault was still there, so obviously the sensor is ********.

Thanks again for the help, I'll keep the thread updated!

Matt

 

[Mattbook]

Mentioned I would update the thread so here I am! Wasn't quite as bad as I thought.

Monday morning I ordered the Bosch sensor (definitely not wanting to do it twice with cheap parts!). And Monday evening after work I started the strip.
Arch liners out, bumper off, passenger side intercooler off and sensor out! Easy.

Sensor came Tuesday while I was at work and that night I fitted it. Intercooler back, bumper back, arch liners back and chocks away.

Struck her up, no more limp mode but EML still on. Did a quick VCDS scan and cleared DTCs. Quick off/on cycle and whola. She's been alright ever since.

Now just wait for the next fault... Haha

 

[desertstorm]

Glad you got it sorted. Things are so much easier with the correct information.