[p_linke]

Finally got around to routing CAN-H and CAN-L from the instrument cluster to the RNS-E. Buttons now light up, but a very strange problem has occurred. Switching on the ignition, and/or switching on the lights causes the radio to ask for the PIN code. If I enter the PIN code, the radio accepts it, and then immediately asks for it again. The radio funtions properly only without the ignition or lights on (not very useful).

Voltage measurements from the CAN are as follows:
CAN-H CAN-L
Key off 0 0
Key on 2.67 2.51
Car on 2.64 2.51
Lights on 2.67 2.51

I ran the CAN-H from Pin 5 of the grey connector behind the cluster and CAN-L from Pin 6.

In addition, I can VAG the radio but I get an error saying there are too many communication problems to continue.

Car: 2001 Allroad (US Version)
RNS-E (EU-Basic) 4B0 035 192 P
Software coding: 0502115

Any help is appreciated.

 

[AudiA4B6US]

Regarding the "too many communication errors", we had that before a couple of times. Once the VAG-COM software was way to old and updating to the newest 504.1 release solved the issue. In the other case the original small navigation unit was still installed and connected in the trunk. Since it is responding to the same address on the CAN-BUS, VAG-COM was talking to both devices at the same time and got confused. Disconnecting the BNS unit in the trunk fix the issue here.

For the unit forgetting the code, try to do a reset by pressing RADIO and SETUP simultaniuosly until the unit reboots. This has helped a couple of times. If it doesn't, make sure that you get permanent 12V+ to your unit and not switched.

 

[PetrolDave]

Voltage measurements from the CAN are as follows:
CAN-H CAN-L
Key off 0 0
Key on 2.67 2.51
Car on 2.64 2.51
Lights on 2.67 2.51

The CAN bus carries high speed digital data so, aprt from proving that the wires are connected to something, voltage measurements on the CAN-H & CAN-L are not a lot of help when fault finding.

 

[p_linke]

Problem Solved

Resetting the radio worked. Thanks.

 

[p_linke]

Yet another problem

Hard to imagine, but a new problem krept up. Nav system works fine since the reset, illumination works, it turns on/off with the ignition properly -HOWEVER - the instrument cluster now shows that I need washerfluid (which is full) and that I have a burnt out brake light (which I do not). Hopefully this will be the last issue.

 

[AudiA4B6US]

Sounds like the plugs are not tight after removing/reinstalling the instrument cluster. We had once someonehere with a similar problem and reconnecting the cluster solved this...