MK6 Jetta TDI hard to start one time then fires up next with one key turn all in summer Tenn weather, why?

[Tankbuster]

Replaced my glow plug relay with a new 530 relay and still have the starting problem when the engine is warm mostly. Noticed if the glow plug on the dash lights up it will start, but if no light no start.

 

[thatwhitejsw]

its possible glow plug relay issue. other friend of mine with MK6 Jetta has exact same issue, replaced the relay, she fires up quickly.

last weekend, I did a swap of glow plug relay from 2015 Passat to 2013 Jetta TDI, noticed she cranks and fires up normally then swap back to the old one, she does it again randomly. have to keep testing it to see if the pattern is the same then replace it. I'm watching her car for a while.

Where's the location for relay? I may have this same issue.

 

[Tankbuster]

Under the hood, the fuse box on drivers side. Installed a new 530 relay, but still have starting problems.

 

[Tankbuster]

Had a car scan done on my TDI.

This code come up 01314 Engine Control Module No Signal/No Communication-Intermittent

 

[super1]

Had a car scan done on my TDI.

This code come up 01314 Engine Control Module No Signal/No Communication-Intermittent

01314 - Ross-Tech Wiki

wiki.ross-tech.com

 

[Tankbuster]

01314 - Ross-Tech Wiki

wiki.ross-tech.com

Thanks for the good information, will start looking for a loose wire or bad ground wire.

 

[Tankbuster]

Not really seeing a bad wire or ground, but still possible just don't see it, so am thinking my ECM is going bad. Is this common? Should I have it checked and rebuilt? If so anybody had this done and can recommended a good internet company that does this.