2 CODES P0118 & U1408

Tiny
BHAMDOC1973
  • MEMBER
  • 2016 BMW 328
  • 4 CYL
  • TURBO
  • 2WD
  • AUTOMATIC
  • 101,000 MILES
Can find out for me what they mean? I had an ECT sensor code so I replaced it and that went away, but these still there
Saturday, September 20th, 2025 AT 2:17 PM

6 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
For the first code I would replace the fuel rail sensor.

P0118 - Engine Coolant Temperature (ECT) Sensor Circuit High Input

U1408 often relates to DSC (Dynamic Stability Control) or transmission module losing data from the DME (engine computer).

I would disconnect the battery and remove the connectors for the DME. They usually have corrosion on them because of where they are located. Please upload pictures or videos in your response
Was this
answer
helpful?
Yes
No
Sunday, September 21st, 2025 AT 9:09 AM
Tiny
BHAMDOC1973
  • MEMBER
  • 2,010 POSTS
But for some reason the p0118 online pops up as the ECT sensor, which what the code reads. I don't have any fuel related codes or issues on this car
Was this
answer
helpful?
Yes
No
Sunday, September 21st, 2025 AT 9:33 AM
Tiny
BHAMDOC1973
  • MEMBER
  • 2,010 POSTS
Attached
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Sunday, September 21st, 2025 AT 9:34 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
I see, I updated the first post, yep, I would swap out the coolant temperature sensor. Here is the location. Clear the codes once the repair is completed. Here is the location of the fan switch so you don't get them mixed up, the engine coolant temperature (ECT) sensor is located on the front of the cylinder head, near the firewall, on the exhaust side. Check out the images (below). Let us know how it goes
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Monday, September 22nd, 2025 AT 11:45 AM
Tiny
BHAMDOC1973
  • MEMBER
  • 2,010 POSTS
Ya I replaced the one on the front, which in previous model Bmw was the one called ECT, not sure why its in the back like you mentioned, other have also mentioned that as well. It is this one here
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Monday, September 22nd, 2025 AT 12:32 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Sorry typo, anyway, that is the one, also this code can come up if the engine has been overheated. Did you clear the codes and has it come back?
Was this
answer
helpful?
Yes
No
Monday, September 22nd, 2025 AT 2:08 PM

Please login or register to post a reply.