View Single Post
      07-11-2021, 07:58 AM   #8
PBGF32
Engineer
PBGF32's Avatar
38
Rep
133
Posts

Drives: 435i M-sport
Join Date: Jul 2012
Location: Florida

iTrader: (1)

UPDATE: Cleared all codes and instantly everything was back to normal. Oil temp gauge working, no CEL. Have driven 3 weeks without issue.

Initially I tried swapping the ECT sensor near the oil filter housing before I had access to someone with OBII setup and that had zero effect. Still got the same -128 C reading.

It looks like the expansion tank leak caused a short somewhere in that instant and the ECU never trusted the reading again afterwards. Once I cleared the codes everything was perfect. (Never actually swapped ECT sensors, just plugged the new one into the harness as quick data point)
Appreciate 0