W205 C220d Exhaust gas temperature (EGT) sensor issue

[ReggieCyde]

Car is 2017 at about 58k miles. Recently had an adblue problem which turned out to be clogged injector, no issues with the N0x sensors. However, EML came back on a few days after repair and I got the following codes on my generic OBD2 reader.

P2084: Exhaust gas temperature (EGT) sensor 2, bank 1 - range/performance problem.
P242B: Exhaust gas temperature sensor 3, bank 1 - circuit range/performance problem.
P246F: Exhaust gas temperature sensor 4, bank 1 - circuit range/performance problem.

I cleared the codes and the EML went out. The car drove fine with EML on, no limp mode.

It seems odd all the sensors have failed? What I need to know is how many sensors has this car got? I assume four? Does anyone know the locations and part numbers please? Even if it's just one that's gone wrong, I might as well replace them all rather than more go wrong in a few months time.

 

[ReggieCyde]

This has the OM651 engine I believe, I think two sensors are located in the engine bay itself, in the area under airbox?

 

[ReggieCyde]

Update: After about 100 miles the EML light came back on with the same fault codes. Again, MPG and general performance feel fine.

After some painstaking research, after finding and refering to webautocats.com it seems the OM651 engine has 3 EGTS.

Part numbers seems to be:
Near the catalytic converter - A0009056404 - (under car)
Downstream of turbo - near DPF - A0009056804 (engine bay)
Upstream of cat - A0009058904 (Bosch 0986259056) (engine bay)

My current approach is to replace both sensors in the engine bay myself. There's a guide on YouTube titled 'Mercedes W212 How to relace temperature sensor OM651 (different car but same engine) amd Mercedes P2081 Fix OM651 EGT Sensor (different error code but same issue).

 

[ReggieCyde]

Edit:

Update: After about 100 miles the EML light came back on with the same fault codes. Again, MPG and general performance feel fine.

After some painstaking research, after finding and refering to webautocats.com it seems the OM651 engine has 3 4 EGTS.

One is located near the exhaust manifold (Pre-turbo). This one is apparently a common failure and the easiest to access.
Part number A0009056404 (Bosch 0986259012) but I don't know if this is for the W205 version of the OM651.

There are three others. Two attached to the DPF and one on the exhaust near the cat.
Part numbers seems to be:
Near the catalytic converter - A0009059705 - (under car)
Downstream of turbo - near DPF - A0009056804 (engine bay)
Upstream of cat - A0009058904 (Bosch 0986259056) (engine bay)

However i'm not sure on some of these part numbers as the OM651 engine was prolifically used across various models in many variants.

My current approach is to replace both sensors in the engine bay myself. There's a guide on YouTube titled 'Mercedes W212 How to relace temperature sensor OM651 (different car but same engine) amd Mercedes P2081 Fix OM651 EGT Sensor (different error code but same issue).

 

[Supernoodle]

Faults for 3 EGTs at the same time? You'd have to be bloody unlucky for them all to fail. Especially so soon after someone had been repaired with the car.

I'd be testing them, the wiring and simulating them before blindly replacing.

 

[ReggieCyde]

Faults for 3 EGTs at the same time? You'd have to be bloody unlucky for them all to fail. Especially so soon after someone had been repaired with the car.

I'd be testing them, the wiring and simulating them before blindly replacing.

It does seem odd that all three are triggering codes while the car doesnt appear to have any symptoms. I think this needs a better diagnosis so I'm booking in a Star session with a local indy and see what it throws up.

 

[deutsch33]

It does seem odd that all three are triggering codes while the car doesnt appear to have any symptoms. I think this needs a better diagnosis so I'm booking in a Star session with a local indy and see what it throws up.

how did you get on with this, i have exactly the same issues??

 

[ReggieCyde]

how did you get on with this, i have exactly the same issues??

The Star diagnostics suggested they were operating within parameters. They have not been triggering a fault from a cold start so this seemed strange as well. They reset the EML, which I could do with my basic OBD2 app but so far unlike when I clear it, it has stayed cleared. So I'm keeping an eye and will see if the fault stays cleared.

 

[SL350_SWINDON]

Did anyone with this issue get any more info? Or can anyone offer advice?
I’m having the same issue:
P2084: Exhaust gas temperature (EGT) sensor 2, bank 1 - range/performance problem.
P242B: Exhaust gas temperature sensor 3, bank 1 - circuit range/performance problem.
P246F: Exhaust gas temperature sensor 4, bank 1 - circuit range/performance problem
All codes exist when EML comes on. Performance is not impacted. I can’t believe it’s all 3 sensors at issue. Maybe a common harness connection or earth point? Any thoughts or ideas please?