P06A3 - Sensor Reference Voltage "D" Circuit/Open

Wow, not much on the web for this error code. The engine light illuminated today on my 2010 Golf TDi and the only code in the computer is P06A3 - "Sensor Reference Voltage "D" Circuit/Open".
I have combed the net, can't find squat on which sensor it might be. The car drives fine, shifts fine and if not for the idiot light, I wouldn't know there is a problem. I've given the engine area a good visual, but all looks normal.

Anyone with any history on this code?

https://www.obd-codes.com/p06a3

Shop key said to verify ecm vref voltage. If it is within spec then to check ground circuit. Spec is usually 5v.

Thanks stamp11127!
I was already on the site your link took me to, the issue with what he is saying is that when he says.."Use your vehicle information source to..." Well, I don't have such a source. I wasn't successful in finding circuit diagrams on the web either. I do have the measurement tools, scope, meter, etc. and checking voltages is easy but I don't know where to check them and if I just start checking every connector/sensor, I don't know if what I find is in or out of spec. I really thought there would be more info on the web on this but man, close to zip.

So, Would you know where to verify the ecm vref? My guess is that a sensor failed in the open state but since the car seems to run as normal, I don't have any clues as to which sensor or which feature, circuit the sensor senses.

I have a similar issue come up on my Jetta, took it to the dealership and this was their reply as to what they have to do;


"Glow plug wiring needs a bridge/bypass from engine control module. Codes in vehicle currently stem from the glowplug codes found previously. Cylinder b and c don’t have power. D and E do. Recommendation would be to have all four wiring leads done at the same time as the labour doesn’t change it would just be the additional two leads.

Takes us 2.5 hours to do the replacements. And this avoids changing the entire wiring harness.
-$297.50+hst

Main Code: DTC P06A3 Sensor reference voltage D open circuit
- Glow Plug b and c are the actual plugs with no voltage going to them."


Not sure if anyone has suggestions on how this is occuring/ if there is a cheaper fix then what they are recommending (after taxes and such they said it'd be upwards of >600$)

Still waiting on them to give me a full quote...

Running autoscan with VCDS would give you better guidance.
I would not let a mechanic who doesn't have VCDS work on my car. Just saying.