I have an engine management light comes on and when I check code comes with  P0684

 Glow plug control module to PCM communication circuit range  performance 

 I can't find any issues with the car as it starts and drives as normal but sometimes when I start it will come on again.  Does anyone have any ideas as my local garage has not?

 I can't find any information about this on the web 

 Any advice be helpful and appreciated as always  

https://www.yourmechanic.com/article/p0684-obd-ii-trouble-code-glow-plug-control-module-to-pcm-communication-circuit-range-performance-by-valerie-johnston

 

Points out everything to look for.

 

Thanks Kris82 I'll check it out

so,  did you check it out?   I went to that site and it was for US or Canadians only?

 

I've got the same issue ...  

 

The other week I got the enginer management light come on.  bought a cable and software and the fault was .. exactly..

 

Stored DTC(S)

P0684 - Glow Plug Control Module to PCM Commmunication Circuit Range/Performance

 

I found a great webiste here ... https://www.obd-codes.com/p0684 which pretty much covered everything ... apart from where all the respective componants live??

 

Anyway ... I reset the code but seeing as the ambient temperature is great today I'm not really surprised the fault hasn't returned.   It's got a its service due in a few months and so I'd really like to sort this myself before then.

 

@Davet30 You dirty old man... dirty! dirty!

 

http://forums.tdiclub.com/showthread.php?t=343503

Edited 19 May, 20206 yr by MicMac