My13 mk7 gti p2556 & p0116

[frogg]

Good morning all. I recently had the Check Engine light come on my car with these codes set.

This is accompanied by erratic temperature gauge performance
- Sometimes reads as high as 120
- Sometimes reads as low as 50 (0?)

If it is on 0 or 120 the fans are running constantly.

When power I power cycle the car the gauge will go to a more reasonable temp, usually somewhere between 70 & 90 degrees.

I have checked the temp via Torque pro OBD and it is not getting above 75 degrees. Also the oil temp is not getting above 75 degrees either.

my *theory* is that the computer is getting bad readings from the temp sensor or the thermostat and running the engine cool to preserve it?

I have checked the coolant level switch by unplugging it and received an immediate warning that the coolant was low - plugging it back in cleared the error.

Just looking for thoughts? I am also considering buying the ODBEleven scan tool but does anyone know if it will give more detailed info that the generic scan tool and torque pro? will it allow me to see specific voltages that are coming from the various sensors on the car so that I can then validate them with a multimeter?

Also, my ACC and front assist is disabled - but from I understand this is a by product of the other errors.

I have attached the Torque Pro scan results, but it does not give much info.

Thanks in advance.

[str05]

Did you work out a solution to your issues?

I'm having the exact same problem and in the middle of trying to troubleshoot. CEL seems to come from a failure in correctly reporting the coolant temp. The coolant gauge intermittently drops to zero as if the car is off and fans go to 100% as a failsafe I guess. A bit strange parking at work with the fans still on 100% after the car is off and doors locked.

I dont live anywhere near a VW dealership or even a euro independent shop so is a bit tricky Looks like the thermostat might need replacing, but its under the intake manifold and not so simple. There were heaps of issues with MKVI coolant leaks/problems but cant seem to find much info with MKVIIs

[str05]

A follow up to this for the next poor unlucky soul.

There were a handful of other codes, but the ones above were the main ones. In the end, it was the thermostat/coolant pump that was ****ed. Ended up buying a VCDS cable, pretty much confirmed it. Thermostat was stuck open, resulting in the car never really getting to temperature correctly.

Im the second owner, but it had always been serviced at VW and serviced on schedule etc. A random VW dealership quoted me around $800-1200 (cant remember) but I pressed them to replace it under ACL even though its out of VW warranty. The dealership maintenance manager doesnt really have a say in if this gets approved, but forwards it on to VW Aus to consider. They came back offering to pay 70%, but asked him to push back stating that its a "major" fault and if I knew this was a likely fault, I wouldnt have purchased it- as per ACL wording. Perhaps because it was also being serviced there, they came back saying theyd pay 100%.

YMMV, but if things are out of warranty and yovue stayed within the VW bubble for servicing, assertively press the dealership to have it covered- never know!