Exhaust gas temperature sensor

[teri946]

My Mercedes g wagon 2015 diesel 350 EML came on and fault is p2080 which evidently is fault with exhaust gas temperature sensor
Despite trying to locate this sensor I just can’t see it.
Can anyone please supply picture of exactly where this is located

 

[bobski1976]

I dont have a pic but isn't it usually located on the dpf part of the exhaust also known as the second cat. just before the dpf begins.

 

[Tony Dyson]

My Mercedes g wagon 2015 diesel 350 EML came on and fault is p2080 which evidently is fault with exhaust gas temperature sensor
Despite trying to locate this sensor I just can’t see it.
Can anyone please supply picture of exactly where this is located

The OM 651 (not sure what yours is but suspect it would be similar if not the same?) has two temperature sensors upstream of the DPF, ref B19/9 and B19/11 further up above the Turbocharger where both are required to be working within parameters for a DPF Regeneration to trigger and complete successfully so if I were in your shoes I would monitor the fill level of the DPF and stop driving before it reaches say 90% fill level and change the faulty temp sensor as a matter of urgency, otherwise you'll have an overloaded DPF to deal with as well and all which that entails!

 

[steveq]

I don't think you have the OM651 engine - it is the 2.1 litre engine.
You 350 is the 3.0 litre, I think?

On my C Class with the OM651engine, that fault was the temp sensor upstream of the turbo. That means that it is bolted into the exhaust manifold. Of course, on the 4 cylinder OM651 there is only one manifold.
If yours is the V6 there are two manifolds.
You'll need to identify which side has gone faulty.

 

[teri946]

Sorry to sound really thick but am I looking in the engine compartment or underneath the car
Code reader said bank 1 sensor 1
The picture shows what I thought was the right part but I am told the exhaust temperature sensor only has two wires to it whereas the part in the picture has four wires

 

[steveq]

On my OM651 engine, it is bolted into the top of the manifold. It isn't visible from underneath.
The manifold is only visible when the air filter box is removed.

 

[Tony Dyson]

On my OM651 engine, it is bolted into the top of the manifold. It isn't visible from underneath.
The manifold is only visible when the air filter box is removed.

What you're referring to is the "Temperature sensor upstream of
turbocharger (B19/11)
The temperature sensor is located on the exhaust
manifold flange upstream of the turbocharger where it
determines the exhaust temperature. This allows the
thermal load on the engine and the turbocharger to be
monitored."

"Temperature sensor upstream of diesel
particulate filter is (B19/9)
The temperature sensor is located in the assembly
upstream of the diesel particulate filter (DPF). The
sensor measures the temperature of the exhaust gas
as well as the thermal load on the oxidation catalytic
converter."

 

[steveq]

Great picture.
On the OM651 there's is a bit of dismantling to be done to disconnect the ECU and take off the air-filter box.
Once they are removed, you'll see the sensor bolted into the top of the manifold with a cable sticking out of it.
Also the cable from the sensor (B19/11 in the picture above) routes around the front of the engine to roughly where B11/4 is in the picture. You need skinny double-jointed fingers to fit it!!
Make a careful note of where the old cable goes before you remove it.

Doesn't help much on your car though.
I assume it must be somewhat similar and, as i said above, you have two sensors.

 

[Mr Greedy]

When I had a temperature sensor error like this (on a non-Merc), I plugged the diagnostics in and had someone in the passenger seat whilst I took it for a drive. Looking at the temperature sensors, you could see which one was faulty, as the temperature readings were erratic/inconceivable. For example, one minute low temp, the next minute high temp, the next minute error.
When I got home and with a cooler engine, to check I had the correct sensor I unplugged it whilst the engine was running, and the diagnostic showed no output. In my case, it was the DPF/exhaust temperature sensor, screwed in through the forward section of the DPF/catalytic convertor metal can.


If you can interrogate live data, you could do the same to definitely identify which sensor, before spending money on parts roulette if you are not sure exactly which sensor it is from the code?