Hello,

I have recently look to my Octavia mk3  2.0 TDI (engine code: CRMB) 17MY and I have noticed that readings of the engine coolant temparature sensors are stange. Depend of the app which I have used I can see two sensors: Engine coolant temperature 1 and Engine coolant temperature 2. The redings for engine coolant temperature 2 showing conatantly -40 deg.

Questions:

1. Does it mean that my engine has a 2 sensors?

2. What impact to engine it might be?

3. Where the sensor 2 is placed in the engine? I was googling, but it showing me place of the main coolant temperature sensor.

To complicate this I have checked on other app (carscanner) and it showing me bit different results and the name of the sensors is different. The carscanner showing me "[ECM] Radiator output coolant temparature: actual" and "[ECM] Radiator output coolant temparature: commanded"

Readings for actual is 2222 deg. where comanded is 80 deg. Questions:

4. Is the "[ECM] Radiator output coolant temparature" sensor the same as "Engine coolant temperature 2"? One of them showing -40 deg. second 2222 deg. Both values are insane.

5. If not the same what is it?

 

I am bit lost in those readings and I will be appreciate for any help. Just to mention that I am trying to find a reason why my car has higher fuel consumption and what I have been learned those sensors might have something to do with my issue.

 

Regards

Florian.

As far as I'm aware there is only one coolant temp sensor on the diesel engines & its G62, on the side of the engine..

According to the wiring diagrams there is only the 1 CTS G62 as stated above, I would get the system checked with something other than that phone app like VCDS I see you're in MK so am I and I have genuine Hex-V2 VCDS 

1 hour ago, Florian_pl said:

The redings for engine coolant temperature 2 showing conatantly -40 deg.

Well, if that were correct, then you'd either be running neat antifreeze or your engine would be frozen solid.

Hi Guys,

I have read that there is a one main sensor for ECU, but I have read that there is another sensor for gauges. I am not sure whether it is true but from some reason two different apps are detecting two sensors.

From other side I need to agreed that app softwares have limitation and cannot be fully trust.

 

Regards

I'd agree with the above, there is only one sensor.

 

The ECU looks like it supports a second sensor depending on which engine it's being used on. The two apps handle missing/unviable sensors in very different ways hence the two (difference) nonsense readings.

 

The temperature gauge uses the same sensor has as the engine. However, it doesn't display the true value, instead it will show a steady 90'C whenever the temperature is between about 75'C and 105'C

 

While the gauge points at 90'C, the car is considered to be running within the normal operating range 

Hi Florian

Did you find the problem? Two years later read topic with same problem as you had in the past. After change sensor on right of engine still same

.

Edited 14 November, 20232 yr by ords

Not running ok when message display on dashboard( cutting pedal and flashing on dashboard).. otherwise al looks good water on level, no overheating