Hi guys, I have a 2004 Mercury Grand Marquis GS with 101,900 miles on it. Runs great, no CEL, up to date on all the maintenance. Here is the data after the engine is warmed up and idling:
Fuel Sys 1: CL
Fuel Sys 2: N/A
Calc Load 19.6%
ECT: 201 F
STFT B1 0.8%
LTFT B1: 1.6%
STFT B2: 3.1%
LTFT B2: 0.8%
MAP: 10 inHg
Eng RPM: 639
Spark Adv: 18.0
IAT: 109 F
MAF: .52 lb/min
TPS: 19.6%
O2S B1S1: .815 V
STFT B1S1: -1.6%
O2S B1S2: .835 V
STFT B1S2: 99.2%
O2S B2S1: .655 V (was .190V in the previous picture, but upon scrolling down it changed)
STFT B2S1: 3.9%
O2S B2S2: .825 V
STFT B2S2: 99.2%
MIL Dis: 0 (miles)
Fuel Pres: 52.2 PSI
I took pictures of each screen and went to the next, then copied into text on here.
Anyway, my first question is why does it say Fuel Sys 2: N/A? Isn’t this only something it would say on a 4 cylinder or an inline 6? It runs perfectly so I don’t know what it could mean.
why does it say Fuel Sys 2: N/A?
you only have one ECM, one MAF sensor, one ECT, one MAP, etc.
One fuel system.
You will never have one bank open loop and the other closed.
So a V8 with 2 banks can have it say OP/CL only on the first one? I thought that was only for a 4 or 6 cylinder? Admittedly I don’t know much about how it works, so maybe you could shed some light.
edit- got it, thank you!
Also, any thoughts on the rest?
All cars.
I've never heard of a vehicle with two computers , two intakes, two sets of sensors etc.
It runs perfectly
There's nothing that needs attention in the data. Happy motoring.
maybe you could shed some light.
even though modern vehicles can modulate air fuel mixture separately for each bank, it only has one intake and one throttle. It can only regulate air intake globally for both banks. Engine and coolant temperature will also be even across both banks. Therefore fuel metering mode is switched in unison from closed loop (pre-set mixture, no sensor input) to open loop (using feedback from O2 data)
The provision may be there for some kind of exotic diesel engines with twin intakes.
Isn't open loop where it’s a preset mixture and closed loop where it gets feedback from the oxygen sensor in order to maximize efficiency?
Yup! Brain fart.
Good catch.
I found some more examples of Crown Vic’s on other forums with live data. Those also seem to say N/A for fuel Sys 2. However, with other cars and other brands of scanners, it will sometimes say CL or OL for both simultaneously if it’s a V6+. I’m assuming it’s how this scan tool is programmed. I bet if it were a different brand, it would just say CL or OL for both on mine.