Engine light On : "Engine Coolant Temp Sensor on Radiator Outlet (G83)"

[Jey]

Hi,

I have a Caravelle T6 150hp diesel, 4 motion, from September 2016. 354 000 Km today.

Yesterday evening, the engine light lighted ON on the dashboard.
I have read default from my phone (it was a "coolant sensor" problem). Then I cleared defaults.

Then when I came back home, the light came back ON.

This morning, I used VCDS to read the list:

1 Fault Found:

16106 - Engine Coolant Temp Sensor on Radiator Outlet (G83)
P2185 00 [10101100] - Signal too High
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 13
Mileage: 354126 km
Date: 2098.01.12
Time: 20:35:39

Engine speed: 1178.75 /min
Normed load value: 0.0 %
Vehicle speed: 25 km/h
Coolant temperature: 87 °C
Intake air temperature: -12 °C
Ambient air pressure: 940 mbar
Voltage terminal 30: 14.375 V
Unlearning counter according OBD: 40
Air mass at air mass meter 1: 57.6 kg/h
Mass airflow sensor 1 bank 1 airflow: raw value: 418.2 mg/stroke
Accelerator pedal travel: raw value: 0.00 %
Outside temperature sensor 1: B1: raw value: -16.5 °C
Coolant fan 1: activation: 10.00 %
Coolant fan 2: activation: 0.00 %
Fuel temperature sensor 1: B1: raw value: 28.2 °C
Coolant temperature sensor 1: B1: on radiator output: raw value: -40.0 °C
Exh. gas recirc. 1 bank 1: act.temp. of water upst. of radiator: 0.0 °C
Fuel consumption: 1.10 l/h
Engine oil temperature: 105.1 °C

Please, do you have any idea?
I used my Caravelle everyday for my work (tourism with clients). I hope it's not a big problem...

 

[n10n]

From your freeze frame: Coolant temperature sensor 1: B1: on radiator output: raw value: -40.0 °C

Could be the sensor or wiring. This is from my 204 engine but most likely it’s the same, G83 sensor is located under the radiator and very visible from underneath once the engine bottom cover (if you have one) is removed.

 

[Jey]

Thanks !

I will inform you soon how we managed.

 

[Jey]

Finally... the garage changed the sensor.
The reference is 06a919 501a
And, nothing is better.

With my phone I still see "Engine coolant temperature B : -39°c"

At the garage, they temporary changed the second sensor : the data is good.

So it seems to not be the sensor.

Is anyone has an idea, please?


This problem is making troubles: the engine's fan is running at full speed, the webasto is not always starting, the start&stop is disabled.

 

[mmi]

With my phone I still see "Engine coolant temperature B : -39°c"

Phone???

Either

(A) there is wiring break and thus ECU sees the minimum negative value (open circuit)

​

or​

(B) The phone is poking at a non-existing sensor. I'm afraid T6 engine does not have coolant temperature sensor B".


Please verify with VCDS. Perhaps you could post engine's blockmap data.

---

Not all diagnostics tools can handle "installed sensor list" properly and thus give readings even from non-existing sensors.​

Below a snippet of T6 coolant sensor installation list:​

​

Install. list for temperature sensors bank 1-Coolant temp. sensor upstrm. of radiator	supported
Install. list for temperature sensors bank 1-Coolant temp. sensor dwnstrm. of radiator	supported
Install. list for temperature sensors bank 1-Coolant temp. sensor in cylinder head	Not supported
Install. list for temperature sensors bank 1-Coolant temp. sensor upstrm. of radiator (SENT)	Not supported
Install. list for temperature sensors bank 1-Coolant temp. sensor dwnstrm. of radiator (SENT)	Not supported
Install. list for temperature sensors bank 1-Coolant temp. sensor in cylinder head (SENT)	Not supported
Install. list for temperature sensors bank 1-Coolant tem.sens.upstrm. of radiator exh.gas recirc. HP (SENT)	Not supported

 

[Jey]

Yes with the phone, I have a Bluetooth OBD dongle who shows 2 Temps.

At the garage the mechanic said with his "computer" he sees -39°c (not with a phone).





I will use VCDS soon as possible.
Im not so confortable with VCDS. Do you know, please, where I should go in VCDS to find this values?

 

[mmi]

Seems to be "Car Scanner" app. Actually the "coolant temperature B" in the app doesn't receive any data - as min/max are both n/a, also the missing numerical value "reveals" that there was no data in the channel.

How-to record all engine data channels - aka blockmap data​

VCDS > Applications > Controller Channel Map >​

For "Single controller address" - 01​

​

Tick/fill boxes as above and click Go. ​

VCDS flashes screens for a moment (when finished click on "Done, Go Back")

The data packaeg will be in file blockmap-01-... in folder C:\Ross-Tech\VCDS\Logs\....
Please post/attach the file

---

How-to monitor live data - coolant sensors G62, G83, G812​

VCDS > Select > Engine > 01-Engine > Adv. Meas. Values > ​

Tick the following

IDE00025 Coolant temperature​

IDE07725 Coolant temperature sensor 1: B1: on cylinder head: raw value - G62​

IDE07727 Coolant temperature sensor 1: B1: on radiator output: raw value - G83​

IDE10312 Exh. gas recirc. 1 bank 1: act.temp. of water upst. of radiator - G812​

​

 

[n10n]

The original error was from VCDS though and clearly reported G83 sensor issue. Also the freeze frame showed 10% fan activation.

Coolant fan 1: activation: 10.00 %
Coolant fan 2: activation: 0.00 %

Has the fan been an issue all the time? I suppose ECU could run the fan as a precaution if it doesn’t see coolant temperature - it’s better to cool bit too much than let engine overheat.

(A) there is wiring break and thus ECU sees the minimum negative value (open circuit)

Sounds like this could be the issue. ”Signal too high” from the original error makes me wonder if this would point to ground wire of the sensor being cut -> signal wire jumps to supply voltage -> ECU knows supply at signal wire is too much -> ECU replaces the measured temperature by a ”safe” minimum.

 

[mmi]

The original error was from VCDS though and clearly reported G83 sensor issue.

Yes, definitely the G83.

Coolant fan 1: activation: 10.00 %
Coolant fan 2: activation: 0.00 %

Has the fan been an issue all the time? I suppose ECU could run the fan as a precaution if it doesn’t see coolant temperature - it’s better to cool bit too much than let engine overheat.

On T6 engines the activation 10% means plain zero current into motor. It has been explained (by Ross-Tech) that electric motors are "coded" in VAG applications to show their normal operating range as 10...90%, supposedly to leave 0% and 100% to indicate fault conditions.

Seems to be the same also with

IDE07798 Heater support pump 1 bank 1 second.circuit: activat. 10 %​

IDE07800 Heater supp.pump 1 bank 1 charg.air cool.circuit: activat. 10 %​

​

However, unfortunately the above is not consistent even within a T6. E.g. in Climatic AC the same is seen as

IDE00971 Coolant fan activation: specified value 0 %​

​

Sounds like this could be the issue though ”Signal too high” from the original error makes me wonder if this would point to ground wire of the sensor being cut -> signal wire jumps to supply voltage -> ECU knows supply at signal wire is too much -> ECU replaces the measured temperature by a ”safe” minimum.

Perhaps the other way round? But anyways a cut wire.

IDE07725    Coolant temperature sensor 1: B1: on cylinder head: raw value    -27     °C
IDE07726    Coolant temperature sensor 1: B1: on cylinder head: raw voltage    4.769     V

IDE07725    Coolant temperature sensor 1: B1: on cylinder head: raw value    83.2     °C
IDE07726    Coolant temperature sensor 1: B1: on cylinder head: raw voltage    1.153     V

IDE07727    Coolant temperature sensor 1: B1: on radiator output: raw value    -28.7     °C
IDE07728    Coolant temperature sensor 1: B1: on radiator output: raw voltage    4.789     V

IDE07727    Coolant temperature sensor 1: B1: on radiator output: raw value    46.2     °C
IDE07728    Coolant temperature sensor 1: B1: on radiator output: raw voltage    2.448     V

 

[n10n]

On T6 engines the activation 10% means plain zero current into motor. It has been explained (by Ross-Tech) that electric motors are "coded" in VAG applications to show their normal operating range as 10...90%, supposedly to leave 0% and 100% to indicate fault conditions.

Seems to be the same also with

IDE07798 Heater support pump 1 bank 1 second.circuit: activat. 10 %​

IDE07800 Heater supp.pump 1 bank 1 charg.air cool.circuit: activat. 10 %​

​

However, unfortunately the above is not consistent even within a T6. E.g. in Climatic AC the same is seen as

IDE00971 Coolant fan activation: specified value 0 %​

Good stuff, still wouldn’t lay my fingers on the fan though!

Perhaps the other way round? But anyways a cut wire.

Oh ok so it works as ”inverted”, higher signal voltage means lower temperature. So… still a potential ground wire issue but just no replacing of the measured value.

 

[Jey]

I did not success to do the first test, MMI, your screenshot was not displayed on the computer I used in the car.

I can try again later.

About the second test, please find the 2 videos here:

2025.03.27 - VCDS - Shared with pCloud

Keep all your files safe, access them on any device you own and share with just the right people. Create a free pCloud account!

u.pcloud.link

On the first, engine running, the second temperature is moving (like a broken wire moving with vibrations ?)
On, the second, the temperature is readded, going up.

Is it normal that the last line is at 0 ?


Thanks for your help

 

[mmi]

I did not success to do the first test, MMI, your screenshot was not displayed on the computer I used in the car.

The blockmap? It's in different path of main menu - Applications - Controller Channel Map

On the first, engine running, the second temperature is moving (like a broken wire moving with vibrations ?)

Yes, looks like every now and then the connection breaks up. Needs to be repaired.

Is it normal that the last line is at 0 ?

Yes indeed - The IDE10312 is always 0 - on quite a few single turbo T6 engine logs of mine, too. Thus perfectly normal.
Another school day. I hadn't realised that but I do see that now also in my log files - thanks for pointing that out

 

[Jey]

I spoke about this screenshot.

https://www.t6forum.com/attachments/1726335099950-png.259151/

Should I do this test, still ?


Thanks

 

[mmi]

I spoke about this screenshot.

https://www.t6forum.com/attachments/1726335099950-png.259151/

Yes, exactly - it's found under Applications >>> Controller Channel Map

Should I do this test, still ?

Yes, please - it's very valuable as a future reference! Just in case...

 

[catfood12]

This old chestnut....

Post in thread 'Coolant temperature sensor 2 location'

15 Apr 2024

It could be the old G83 sensor problem;

EML/CEL and radiator fans running constantly

After around 700 miles of mainly motorway driving last week, I got a CEL. Also noticed that the radiator fans were running constantly. That was when I arrived home after a long drive, not stuck in traffic. Same next morning from cold, CEL and fans running constantly. Van still ran well, it did...

www.t6forum.com

• catfood12

• 

and

Thread 'EML/CEL and radiator fans running constantly'

21 Mar 2022

After around 700 miles of mainly motorway driving last week, I got a CEL. Also noticed that the radiator fans were running constantly. That was when I arrived home after a long drive, not stuck in traffic. Same next morning from cold, CEL and fans running constantly. Van still ran well, it did take ages to warm up next day though.




VCDS gave me this;



Engine ECU showing this;



Then when a bit more warmed up.



Then completely lost the plot!




Looks like the G83 sensor on the radiator hose has failed. I think we can rule...

• catfood12
• 06a919501 eml
• Replies: 29
• Forum: Engine, Gearbox, Exhaust, Drivetrain

• 
• 

As has already been suggested, and was my issue, broken wires inside loom to the sensor.

 

[Jey]

Thank you.

MMI, please find the file.

 

[mmi]

Thank you.

MMI, please find the file.

Thank you very much!

Yes indeed - The IDE10312 is always 0 - on quite a few single turbo engine logs of mine, too. Thus perfectly normal.

In the ECU there is an entry in temperature sensor installation list which explains why the sensor is actually missing:

IDE10225-MAS09663

Install. list for temperature sensors bank 1-Coolant temp. sensor upstrm. of exh.gas recirc. cooler HP

Not supported