99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
I have the code P1248 on my 99 7.3. I get the code from my Supertuner 1705 diagnostics. The code is "Turbo boost not detected". I can hear a more pronounced knock in the engine as of lately. My boost gauge seems to register boost just fine. Does anybody have any idea as to what and where I can begin to start looking at? I have 136k on the clock, Donaldson air intake, Supertuner 1705 set on Tow Safe mode. Any help, pictures, etc. would be greatly appreciated.
Early 99 ford psd cc 4x4, SCMT, 3-Gauges, A-pillar
That code means that the PCM isn't detecting boost. It gets it's signal from the MAP sensor, and depending on how you have your boost gauge plumbed, the sensor may not be seeing the same boost that your gauge is.
P1248 - Turbo boost pressure not detected
MAP hose, (maybe the one to the MAP sensor is plugged)
sensor, (possibly defective or plugged)
EBP sys, intake leaks, turbo (probably not because your gauge reads OK)
I'd be checking the MAP sensor hose to make sure it's clear, and also check the hose nipple on the sensor itself (be careful not to damage the sensor).
Let us know what you find. And maybe do another scan to see if you get any other MAP related codes.
Here is a Photo posted by one of the members. The MAP sensor is shown on the left side of the photo with the tubing and wire connector (with red clip) coming from the bottom.
As far as cleaning it, just don't poke something into the nipple and possibly mess up the sensing diaphragm (or whatever it has in there). If you can see something stuck in the nipple and completely plugging it (maybe a bit of rubber from the hose?), it needs to come out, but the main thing is that air needs to get between the intake manifold and the MAP sensor. If you can blow thru the hose, then it's OK.
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