Author Topic: Ambient air temp fault linked to poor performance?  (Read 3742 times)

Offline Ajb1992

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Hello all - first post so thanks for having me.

Recently bought a 2016 MK7 GTI PP at 18000 miles from VW.
I’ve noticed that the external air temperature is always at least 10 degrees higher than the forecast high for the day. I need to have a look at the sensor for damage/obstruction.

My question is whether the engine uses the ambient temperature sensor. I have found the car quick but it doesn’t seem to be as Jae dropping fast as I was expecting. I’m not sure whether my expectations were wrong or whether the ambient air temp fault has something to do with it or whether there could be other issues.

Any help much appreciated.

Offline mcmaddy

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Re: Ambient air temp fault linked to poor performance?
« Reply #1 on: 14 July 2019, 11:04 »
Cooler air temperature should help performance. I would try filling with decent petrol like shell vpower for three or four tanks as you don't know if the previous owner was just chucking supermarket crap in (Tesco momentum excluded).
TCR, Pure Grey, DCC, Dynaudio and Climate Screen.

Offline fredgroves

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Re: Ambient air temp fault linked to poor performance?
« Reply #2 on: 14 July 2019, 11:14 »
Its possible that its using the ambient air temp sensor for mixture adjustment, so I'd probably get that fixed.

It *could* be a problem more than just a cosmetic one.

In theory that sensor is reading temperature under the car and that there are other sensors on the engine air intake that govern the ECU decisions, but I'm not sure...
Current: Mk8 GTI DSG, Adelaides, DCC, HUD, HK, Winter Pack, Rear Camera.. Aka "HMS Weasel"

Gone: 2017 Mk7.5 GTD,manual, NavPro
Gone: 2014 Mk7 GTD, manual, NavPro, DCC

Offline boardlord

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Re: Ambient air temp fault linked to poor performance?
« Reply #3 on: 14 July 2019, 13:57 »
We had the same fault on our Disco.

High temp reading caused the following issues,

Climate control was always blowing too warm, fuel consumption was a lot higher, didnt notice an effect on performance as its a 180bhp diesel, but suspect with the lower MPG it may have been altering the engine mix?

LR fixed it with a software update
2019 MK7.5 GTi PP, 3dr, DSG, Indium Grey, Heated screen, Pan roof, 90% tints.

Offline topher

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Re: Ambient air temp fault linked to poor performance?
« Reply #4 on: 15 July 2019, 22:13 »
nope nothing to do with engine performance, the engine has its own intake air temperature sensor

Offline golfdave

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Re: Ambient air temp fault linked to poor performance?
« Reply #5 on: 18 July 2019, 09:52 »
The engine does use the G17 sensor to correctly calculate the mixture...

When a stone took out the external G17 Air Temp sensor on my Mk7 it threw up all these codes:-

01-Engine -- Status: Malfunction 0010
03-ABS Brakes -- Status: Malfunction 0010
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
10-Park/Steer Assist -- Status: Malfunction 0010
13-Auto Dist. Reg -- Status: Malfunction 0010
15-Airbags -- Status: Malfunction 0010
17-Instruments -- Status: Malfunction 0010

Yes I have just included the headline module codes & not the details as I am copying from my build thread on another forum....so much relies on the external ambient temp data...

EDIT...

Here is a thread I made on the Ross-Tech forum giving a warning & all details about this & the G17 sensor

https://forums.ross-tech.com/showthread.php?12542-WARNING-about-G17-Ambient-Temperature-Sensor-VW-Golf-MK7

« Last Edit: 18 July 2019, 09:58 by golfdave »

Offline fredgroves

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Re: Ambient air temp fault linked to poor performance?
« Reply #6 on: 18 July 2019, 10:10 »
Interesting!

Where is the sensor that it can take a stone hit Dave?
Current: Mk8 GTI DSG, Adelaides, DCC, HUD, HK, Winter Pack, Rear Camera.. Aka "HMS Weasel"

Gone: 2017 Mk7.5 GTD,manual, NavPro
Gone: 2014 Mk7 GTD, manual, NavPro, DCC

Offline golfdave

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Re: Ambient air temp fault linked to poor performance?
« Reply #7 on: 18 July 2019, 11:53 »
Interesting!

Where is the sensor that it can take a stone hit Dave?

its behind the lower front grille under the license plate...

Offline mcmaddy

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Re: Ambient air temp fault linked to poor performance?
« Reply #8 on: 18 July 2019, 17:14 »
Interesting that when a suicidal pheasant decided to re arrange my front end my outside temperature sensor was imbedded in its ar4e when I pulled it out. The only error I got was front assist not working due to the Acc sensor being completed removed from it's bracket. No other errors or warnings and the car drove perfectly fine until it was repaired.
TCR, Pure Grey, DCC, Dynaudio and Climate Screen.

Offline topher

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Re: Ambient air temp fault linked to poor performance?
« Reply #9 on: 19 July 2019, 00:01 »
The engine does use the G17 sensor to correctly calculate the mixture...

it tells the climate control to turn the rad fans on when it fails, its on the convenience bus not powertrain. mixture control reliant upon a sensor mounted in the bumper seems ridiculous to me but if you have found something in an ssp or funktionsrahem for simos 12/18 to the contrary I'd love to see it.