Hello everyone,

I have a 2002 Ford Super Duty F350 7.3, the issue I have is my EBP. My Edge CTS3 monitor shows trouble code “P0472;Exhaust Pressure Sensor A Circuit Low.” How do fix this? My exhaust pressure reading from the monitor doesn’t change and is stuck at 29psi, from the time it starts and while driving “29” doesn’t change. Anyone know what the problem is or had this issue before? The EBP tube, sensor and pigtail all have been replaced. Ford OEM. I just replaced the sensor with another new OEM one and still same issue.

Any and all help would be appreciated, just want to get this fixed. It’s driving me crazy. Thanks!

 

If it insists that the circuit is low, that means broken connection somewhere. Time to open up the wiring harness and start tracing. With that said, if I were going in there, I would start at the big plug on the bracket over the left valve cover. Make sure the connectors are clean and also that the wiring harness hasn't rubbed through on the bottom of the bundle where it makes contact with the valve cover itself.

 

I’ll give that a try when I have some time, probably over the weekend. I know when I had looked over at that area “bottom of bundle”, it looked fine that was a while ago and I even zipped tied it up out of the way. Making sure it didn’t make contact with something for it to rub. Perhaps I overlooked something.
just not sure why my cts3 would be stuck with the 29psi value. Tried clearing the code and just stays there.

 

Does the cts piggyback the factory sensor or does it have it's own dedicated sensor? If no sensor then the factory sensor; trouble is likely at fault there too.

 

only sensor I have piggybacked to the cts3 is the egt sensor I installed to the exhaust manifold. The EBP is not, don’t see how it reads all the other sensors fine except this one. Reads, baro, map, oil, egt..etc just fine

 

Most of these monitors get EBP off of OBDII.

 

right, my issues is that it’s not. Monitor shows “29” and doesn’t change. Only thing I can look at is a broken connection in the wiring harness somewhere.

 

Log with FORScan and see if that is what OBDII is reporting also.

When was the last time the EBP tube and sensor got cleaned/replaced?

 

Which is shielded from a direct connection to the actual sensor. OBDII is specifically designed to report what it sees and not necessarily what is actually happening. To know what's really going on you have to bypass OBDII reporting and access the actual systems.
Statement is the end result of what I learned when I had to go back to school to be a certified emission repair shop. There's a lot more to be said about that, but I don't have that much time. Just know that what OBD reports isn't necessarily what is actually happening. OBD system is installed on every vehicle manufactured for the US market and it's only job is to report what the actual engine management system is telling it so far as being emission compliant and has no requirement to go any farther than that. But there are other things that need to me monitored at times that are not part of OBD and that is NOT reported. Just remember OBD isn't actually the engine management. It just report what the actual engine management system tells it, even it that value is a default substitution for what is ACTUALLY happening. So you'll see some BS data sometimes through OBD, but it's not actually what is really happening. Made my life as an auto repair tech real fun some times.
Very grateful to be retired now.

 

@Kwikkordead That is what I am thinking too. I wonder if 29psi is the default EBP reading for when the PCM thinks the EBP sensor is incommunicado.

 

sensor last night, tube like half a year ago; took it off the other day and it was clear and not clogged. Pig tail also done recent. All OEM parts

dont have a FORScan, link or suggestions appreciated

 

Yes. If the information we are discussing is from OBD, then the information about that sensor has to be directly access via the wiring harness, or a diagnostic system that is designed to go around OBD and directly interrogate the engine management system. That requires specific coding that I know nothing about, but lots of talented programmers can take it from there. Just about every high end diagnostic system such as Snap-on, Matco, etc have that capability. I don't know if ForScan does or not, but I would be surprised if it didn't

 

Reproduced from the Tech Folder at the top of this forum.

FORScan

• FORScan Instructions - PC
• FORScan Lite Instructions - Android
• FORScan Lite Instructions - iOS
• FORScan Data Log Conversion
• PERDELs via Forscan
• Cruise Control/Speed Control Forscan function test
• Speedometer Calibration Using Forscan - Thread
• Speedometer Calibration Using Forscan - Video
• FORScan + FORScan Lite: Class Tutorial Q&A

 

Have you checked the harness at the 42-pin connector above the DS valve cover for damage from rubbing on said valve cover?

 

Someone also mentioned that above, but last time I checked everything seemed fine. I’ll have to take a closer look, I may have missed something. I had zip tied the harness away from the valve cover to this to no be an issue.