2012 Jetta TDI Flashing Glow plug, limp mode, p0045 code

BrianDime

Well-known member
Joined
Apr 23, 2005
Location
Goldsboro, NC
TDI
2012 Jetta TDI
When pulling out in to traffic the other day, my Jetta went in to limp mode and the glow plug light started flashing. I check it with a code reader and it gave P0045 "Turbocharger/Supercharger Boost Control 'A' Circuit/Open" as the only error code. Since then, it has happened a few more times, but not on every trip. Some of the reading I did sounds like it's either a bad boost control solenoid or bad wiring to that solenoid, but some other sources mentioned EGR valve issues as a possibility.

Any one have any suggestions? In particular, I'm not sure how to go about troubleshooting. Should I just order a new Boost servo and see if that fixes it?


Thanks!
BrianDime
 

BrianDime

Well-known member
Joined
Apr 23, 2005
Location
Goldsboro, NC
TDI
2012 Jetta TDI
Additional info: So far, every time it has happened, turning the car off and re-starting it seems to clear the error. Maybe that is useful info for someone.

Thanks,
 

nord

Veteran Member
Joined
Mar 5, 2010
Location
Southern Tier NY
TDI
All turned back to VW. Now a 2017 Hundai Tuscon. Not a single squalk in 10k miles.
The reason (I believe) there are no suggestions or comments is that possibilities are nearly endless. It would appear from the error message that your problem is electrical, not mechanical. If correct, then I'd guess an intermittent open somewhere in the circuit. The causes for such a problem range from a broken wire to any failing electrical component or connector in the circuit. This to include a poor ground which might well cause the ECU to see the circuit as open. Obviously a failing solenoid could be at fault. Then again, so could a corroded ground lug.

I tend to think not the EGR circuit because of the code. By this I mean neither the electronics or mechanicals of the EGR system. While the boost and EGR systems are intertwined and one system will effect the operation of the other, your present code doesn't raise any flags to indicate a failed component on the EGR side.

By the way... I learn every day and have found that the illogical before a problem is located is usually very logical after. Troubleshooting is often a matter of experience and intuition. Sometimes the result is that we first eliminate what experience has suggested, then move into new territory.

The one thing I wouldn't suggest is randomly throwing components at the problem. I've found that this often compounds a problem rather than solving anything. It's also needlessly expensive as we usually don't get lucky on the first try.
 

BrianDime

Well-known member
Joined
Apr 23, 2005
Location
Goldsboro, NC
TDI
2012 Jetta TDI
Thanks for the info! I was afraid it was going to be difficult to locate, and was hoping someone had seen it before.
 

nord

Veteran Member
Joined
Mar 5, 2010
Location
Southern Tier NY
TDI
All turned back to VW. Now a 2017 Hundai Tuscon. Not a single squalk in 10k miles.
Find someone locally (a member here) with VagCom. Generic code readers merely suggest. VagCom, while not always pointing directly to the problem, will allow you to eliminate possibles.

Understand... We've seen many problems that display similar symptoms. Unfortunately the problem described can have many causes. This is why the silence. You really need a tool that will interrogate the ECU in detail. I'm sure there will be information there which will assist in the repair of your car.
 
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