Northstar Engines and System Technical Discussion Discussion, Octane reading in Cadillac Engine Discussion; On my 95 STS while in "pcm data mode" there is one of the data reading's that tells you the ...
On my 95 STS while in "pcm data mode" there is one of the data reading's that tells you the Octane reading,,,,PD42,,, mine is reading "0"....WHY ????
PD42 Octane Level of Fuel
Display shows the octane level of the fuel based on recent knock sesor activity. This parameter will only display 0, 87, 90, or 93 indicating the fuel octane calculated by the PCM. A parameter value of 0 indicates the PCM has not had enough time to calculate the octane level. Display will always read 0 for vehicles with LD8 (270 h.p.) engine.
by the way what were you looking for. was there a problem or were you just playing with your car i know it's a neat feature..
also if there are any codes or snap shot data don't just erase it because it can be very helpful for diagnosing problems, especially intermitant problems