Hi, i’m the original owner of 2008 528i. I had a broken radiator hose last week—Water Coolant Hose Thermostat to Front of Engine. After replace the hose and bleeding the coolant system, everything is fine except Check Engine light is on. The code is P165F.
I want to check the coolant temp. After going through the steps (VIN #) and got to #7, it won’t display any temperatures. Instead, it went back to home display (time and outside temp). I knew I did 100% correct trying to display the engine temp. But nothing is showing.
Engine fan seemed kicking in and out properly. Car is as smooth as always.
i checked all the fuses including those in engine computer. All seemed find. I replaced coolant temperature sensor. Nothing changed. The gas cap is in good condition no cracks.
i hope some of you had similar experience, and can provide some tips to fix this annoying issue.

 

That code has nothing to do with what happened to your water hose. Was the light on before it? You need to have your DME checked out and or updated. Also check your heater circuit fuse

 

The check engine light was on only after the leaky coolant hose replaced and system bleeding is done. I checked all fuses, glove box, trunk, and including those in the ECU. All fuses are fine. My biggest concern is why the engine coolant temp doesn’t show up at all. Thanks