HT4100 4.1, 4.5, 4.9 Discussion, What is F15 code? ('90 DeVille 4.5) in Cadillac Engine Technical Discussion; What controller has an "F" prefix? What is F15? My manual doesn't list it.
(Periodically I check the display codes ...
Automobile(s): 1993 Coupe Deville 2006 XLR Infrared, 2009 XLR-V Crystal Red
Orange County, CA
Re: What is F15 code? ('90 DeVille 4.5)
BCM codes are prefixed by an "F". First pass are PCM codes displayed as "E". Then "EE" indicates the second pass of the PCM codes, and these are current trouble codes. Anyway, a F15 code is SUN LOAD SENSOR CIRCUIT. This by the way does not turn on any light. Code F15 will set if circuit 590 is open or shorted to ground. That circuit goes from position C7 of the BCM to the 40-way I/P to dash to the sun load sensor. You need to get to BCM data parameter P.3.2 and check the value of 0 to 255. So you can have a wire problem, sun load sensor failure, or a BCM failure. I don't know where the 90 Deville sun load sensor is located. I do know that it is in the RH speaker grille top of dash on the 92 and 93 model year. Does your twilight sentinal work?