K-line RNS-E

[polmark]

Hi everyone

Got a weird problem with rns-e and hoping you can shed some light.

VCDS does not comunicate with RNS-E (factory fitted). All wiring is correct at the rns-e.
NOW, when i test the wiring the resualts are as follow:
Diag socket (pin 7) to k-line on rns-e --> no continuity
Diag socket (pin 7) to k-line on climate unit --> continuity ok
k-line on climate unit to k-line on rns-e --> continuity ok (logically speaking, if I should be able to comunicate with radio if vcds finds addr 08 (Auto HVAC) ??????


When I disconnect rns-e and run the test on instruments or electrics, the I get an error
that rns-e not detected (which is correct), with rns-e reconnected error disappears, but still
no connection via vag-com.

Any ideas ??
Thanks

[slippyr4]

The RNS-E is on K2 (pin 15) (there is a second, totally separate pin in the diagnostic socket which is a 2nd K-Line, on most A4's the radio is the only thing on it).

My guess:- Your clone VCDS cable has a broken or missing K2 interface.

Test: continuity between RNSE K-line pin and diag socket pin 15. If that works then that's probably your problem.

Incidentally, I have found previously that VCDS's "clever algorithm" for selecting which K-Line to use is simply to try and contact a controller on both K-Lines and use the one that succeeds. Therefore, if your VCDS cable is broken (assuming it's a legitimate one of course) then you could probably hotwire the vcds cable into the plug (pins 4 and 16 for power, and then VCDS pin 7 (K1) to the car's pin 15 (k2). It will then work but only for the RNSE, but don't blame me if you kill your cable / laptop / car / dog.

[slippyr4]

Hi everyone
When I disconnect rns-e and run the test on instruments or electrics, the I get an error
that rns-e not detected (which is correct), with rns-e reconnected error disappears, but still
no connection via vag-com.



That is because the instruments talk to the RNSE via CAN not the K-Line. RNSE uses KLine only for diag and programming. Assuming you're retrofitting you just need to get it programmed one time only and you're done.