X5 F15 check head Unit ( NBT )

[Marc412]

Hi

With ISTA or Esys, is it possible to check the Head Unit ( NBT) ? or with another software?

[CatalinP]

What exactly do you want to check?

[Marc412]

I have a poor radio reception , radio is playing vey poorly.

I have already check the Amp and the antenna with ISTA , it says they are OK.

So i guess , it could be dommage in the Head Unit.

This is what i would like to diagnosis the radio head unit.

Other ideas to fix this problem are welcome

[CatalinP]

I would rather look at the diversity antenna.

[Marc412]

the antennas have also been checked with ISTA. The test result is O.K for antenna and amplifier

What is strange is that I receive different radios correctly, and at times there is a reception cutoff with a small boom, boom noise, boom, with no reception radio, like if there is no antenna connected. And reception will restart after a few minutes.

[Marc412]

Originally Posted by CatalinP

I would rather look at the diversity antenna.

Is it possible to have a different test than ISTA for antennas? May be to measure the resistance value?

[CatalinP]

Try asking on this forum: https://cartechnology.co.uk/forumdisplay.php?fid=61

[Marc412]

It seems that if i disconnect the purple connector going to the head unit the reception is better. This looks stange?

According to the document , it is ANT FM2 and also: Signal line for the Diagnosis, AM/FM/HF signal, HF signal for Diversity function

The resistance of the rear window antenna is about 7 ohms. Is it good?

Ista diagnosis gives no defect.

Is it a problem with the head unit?

[Qsilver7]

This isn't an answer but just an anecdote...my 99 e39 540iT had horrible static when listening to AM radio stations. One day I was loading CDs into the CD player that was located in the left rear cargo area and somehow/someway the wiring that ran in that area (above and behind the insulation) was slightly moved.

The radio happened to be on in all its static glory...and in that brief instant...the static went away. Hmmm, I thought...so I reached up to intentionally move the insulation and wiring and it went away again. So I peeled back the insulation to see a large bundle of wires and again, when pushed up higher (away from the CD changer, amp and other electrical components...the static ceased.

So I took some electrical tape to secure the wiring higher up...and from that day forward...my 540iT never had a static issue with AM stations (nor any other stations).

All that to say...what happens if you wiggle that wire or connector? Could it be getting interference from some other component nearby?

In the diagrams below...you can see that the antenna is built into the rear left cargo window of the Tourings and SAVs of that time...plus there was an amp/receiver and all the electrical audio/telephony components in that corner...and somehow the wiring had dropped low enough to pick up interference.