OBDII freeze frame data interpretation

Freeze Frame:


Fuel SYS1 CL

Fuel SYS2 N/A

Load PCT 27.1

ETC (F) 181

ShrtFT1 (%) -2.3

Long FT1 % 26.6

FPR (psi) 59.2

Map kpa 11.5

The “ETC” means the coolant temperature is 181 deg F. That’s a typo, it probably says ECT, right? Engine coolant temperature. That seems ok.

Short and Long term fuel trims. A 26.6 % long term fuel trim means the computer is needing to inject an extra 26.6% more gasoline (to satisfy the O2 sensor) than it thinks would be required for that operating condition. That’s a problem. The engine is running too lean for some reason.

That’s probably the fuel rail pressure, 59.2 pounds per square inch. That sounds ok. Verify by checking the fuel pressure specs for your engine.

MAP == manifold absolute pressure of 11.5 kpascals . A kpa is about 0.15 psi, so that’s about 1.7 psi. Or 3.5 inches of mercury. I think that’s too low. The typical idle manifold would be around -20 in hg vacuum, or about 30-20 = 10 inches of mercury absolute. (30 inches of mercury is sea level atmosphere pressure) . It appears you may have a problem with your MAP sensor. That could cause a lean condition. (Double check that your MAP reading isn’t adjusted to sea level pressure, if so that would change the diagnosis.)

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Yes, it is interesting that the diagnostic code is for fuel pressure rather than for the map sensor.