AMG GTC Coolant Temperature Sensor

[andreas_t]

Hello folks - Looking for some help please.
My AMG GTC MY21 (WDX190) with 178.980 engine has developed a problem with the coolant temperature sensor (DTC is P012800) which brings up the CEL.
The local mercedes dealer is currently investigating, but has informed me that replacing the sensor invoves dropping the engine - at significant cost.
Car only has 15K miles and has been religiously looked after.
Would anyone with access to WIS be able to:
1. Check the position of this sensor and advise
2. Check if indeed the engine needs to be dropped for such a repair/replacement

Many many thanks in advance - looking forward to your help

 

[Jobsworth]

LS2 engine, but temperature sensor B11/4 should be in the same place. Doesn’t look like engine out to me, but if they are talking about replacing the thermostat unit, that is a big task. I have a GT coming in Tuesday, so could check position of the sensor then if you like

 

[andreas_t]

View attachment 171422
LS2 engine, but temperature sensor B11/4 should be in the same place. Doesn’t look like engine out to me, but if they are talking about replacing the thermostat unit, that is a big task. I have a GT coming in Tuesday, so could check position of the sensor then if you like

Thank you - this is most helpful.
It would be great if you could check on Tuesday and let me know.
If, indeed, it is at the same place, then it looks like a relatively straightforward job - I can't have a look myself as the car is at the dealership over the long weekend; they want to run a test on the thermostat when the engine is cold which they will do on Tuesday morning
When I go to pick it up I will get clarity on what it is they are proposing to replace.
Incidentally, I found that this fault code is the subject of a Technical Service Bulletin and - even more interestingly - MB USA has extended the warranty of this item to 15 years.

The TSB link is: https://www.nhtsa.gov/?nhtsaId=11015052 - this has the extended warranty letter as an attachement.

Looking forward to any news you may have.

 

[alexanderfoti]

Your codes is indicative of a thermostat failure more likely than the sensor IMO.
If your oil temperature also fails to get HOT (80+) and stay there then its likely going to need a thermostat, its a sizeable job and engine out on the GT due to a supporting beam directly in front of the housing.

On other cars its front bumper/radiator pack/Charge coolers off.

 

[andreas_t]

Your codes is indicative of a thermostat failure more likely than the sensor IMO.
If your oil temperature also fails to get HOT (80+) and stay there then its likely going to need a thermostat, its a sizeable job and engine out on the GT due to a supporting beam directly in front of the housing.

On other cars its front bumper/radiator pack/Charge coolers off.

Thank you - very much appreciated.
The oil temperature this morning on the way to the dealer - circa 10 miles - was at 93C
Coolant went to 90C fairly quickly (less than a mile or so). Stated steady ss per usual and only got to 95C or so when I was caughtin nose to tail traffic..
Frankly, the car behaves as always - I just feel a reduction in power when the engine light comes on (but that could be the placebo effect)

 

[alexanderfoti]

The issue (and code) will likely only be logged on faster roads with lots of airflow. At this point the tempreature will start to drop, in town or slow speed stuff, a dodgy thermostat won't show up.

 

[andreas_t]

The issue (and code) will likely only be logged on faster roads with lots of airflow. At this point the tempreature will start to drop, in town or slow speed stuff, a dodgy thermostat won't show up.

Sounds like i need to take it for a nice drive. After Tuesday
Thanks again !