Howdy, I need help figuring out what to do to fix these two codes, this is on the rig that my wife drives and she is scheduled to be at 4 different shows (horse) this weekend and the truck keeps throwing these two codes. the first is# P0470 "Exhaust Back Pres. Sensor Circuit Error" and the second is# P0478 "Exhaust Pres Ctrl Valve High Input". Please help get these figured out so we'll have piece of mind with her out on the road this weekend! One other question, how do you know if your EBP sensor is junk, I took the sensor off the rig and the sensor tube and cleaned all the soot/carbon out of them and it didn't help the codes. Thanks... oh yeah, it's a 2000 F-350 PSD, auto tranny, and 3:73 rears. about 178K miles.

 

I cant help you but this will bump you up.

 

Welcome to FTE. What are you using to pull your codes? Can you monitor PID's or just pull codes? Have you cleared the codes and they still return after your tube cleaning? Did you inspect the tube to make sure their are no holes in it?

It will take a scanner capable of checking certain values to do an in depth test but here's one you can do without that.

SIGNAL GROUND CIRCUIT CHECK
• Disconnect EBP sensor harness connector.
• Measure resistance from pin A circuit 359 (GY/RD) to chassis ground.
Is the resistance less than 5 ohms?
Yes
INSTALL a new EBP sensor. RESTORE vehicle. CLEAR DTCs and RETEST.
No
REPAIR open in signal return circuit 359 (GY/RD). RESTORE vehicle. CLEAR DTC and RETEST.

 

Thanks for the bump and the reply, it's already more info. than I've gotten on some other forums. Any how, I'm using my micro-tuner to check codes with, and yes I have cleared them several times and tried different things (stock, "tuned", stock w/ trailer, "tuned" w/ trailer, etc. etc.) to narrow down when and why it's doing it, so far nothing has helped or made it NOT throw the codes. As far as monitoring PIS's, that'd be a ???. I did check the tube, a few pits, but no holes. I also did the formentioned ohm test, that came up infinate ohms, needle didn't budge. So, where to go from here? thanks again for the replies.

 

PID's are parameter identifications. Things like volts, pressure, etc.

For example the first step in testing the 0470 code is to select the EBP PID and check for a reading above or below 18.5 PSI. If you had something like the AutoEnginuity scanner that was capable of taking these readings I would give you the whole test procedure.

 

Sorry. I glanced over this part. You might need to test Pin A to ground with the sensor plugged in. Just make sure you seal anything back up so water doesn't get in there later.

 

O.k. thanks for the info on the PID's, in other words....some pretty high dollar, professional epuipment! lol. I'll retest the ohms on that circuit in the morning, like I said earlier it's the wife's rig and she's fixin' to leave for work (3rd shifter) in just a little bit so I have to put everything back together. Thank you soo much for your help and knowledge, like I said, it's a whole lot more than I've gotten from the other forums I've asked on. I feel like we're getting somewhere now!! One other question... Is the 478 code causing the 470 code, or are they two seperate things?

 

DE17 CONTINUOUS DIAGNOSTIC TROUBLE CODE P0478
• DTC P0478 indicates an excessive back pressure condition existed during normal driving.
• Possible causes:
 stuck EBP butterfly valve
 restricted exhaust
 plugged EBP sensor line
 misadjusted EPR linkage
 F-Series wastegate turbo may be overboosting
• Access PIDs MGP and RPM.
• Road test vehicle selecting the best gear to achieve a 2500-3000 rpm acceleration.
• Note the highest boost pressure. This is best accomplished either climbing a hill or with the truck fully loaded.


DE18 INSPECT BUTTERFLY TANG



• Visually inspect butterfly tang.
• Refer to Section 4A or Section 4B , Diagnostic Subroutines, Performance Diagnostic Procedures, Exhaust Restriction for exhaust back pressure regulator tang position illustration.
Does tang reflect an open position?
Yes
GO to DE19 .
No
REPAIR damaged linkage or butterfly valve as required. RESTORE vehicle. CLEAR DTCs and RETEST.

DE19 EXHAUST RESTRICTION CHECK
• Select EBP PID.
• Engine running.
• Accelerate engine to WOT while observing scan tool reading.

Are you starting to see a pattern with the PID's yet? The cost depends on what you consider a lot of money. The cheapest place to buy the AE with the enhanced bundle you will need for the truck is AutoEnginuity PC Scan Tool (USB)

 

F350-6, thanks again for all of this great info. Are these diagrams and procedures from one of these PID scan programs? That is a lot of money for me, BUT I can see how it would pay for itself if it keeps ya out of the repair shop (Dealership or other) just once. My fear is that I'd save up and get one, then be too stupid to use it properly and actually "do something with it". I'll touch base tom. after I get a ohm reading on that one circuit and check the butterfly valve a little closer.

 

No, the diagrams and procedures are from the Ford service manual DVD, but they don't do you much good unless you have a way to monitor the different sensors.

 

O.K. I was finally able to get an ohm reading on the sensor with it pluged in this time, it registered 0 ohms, the needle fell all the way back over to 0. So I take it that means the sensor is junk? Don't want to replace many of these if it's not necissary, they're $138.00 at the sealership! ouch. and another $52 for a new tube if ya want that.
I definately see how one of the DIP readers would help narrow things down for ya and give ya a much better picture of what's going on where. Maybee someday...

 

Well according to the manual, everything is pointing toward a bad sensor or a bad PCM, but a bad PCM is listed as an option on so many things I usually ignore that part.

Is your wife still taking the truck tomorrow? If you have a little time to wait on the parts you can PM Ed Ford Truck Enthusiasts Forums - View Profile: FTE/PARTS-GUY

He's one of our sponsors here that is a Ford dealer who sells parts at a discounted price. Shoot him a PM and see what he would charge for the sensor.

 

actually they started tonight! They'll still be going for the next three days too. Our local dealership can have it for tom. so I said "get it". I didn't know anybody on here could get parts! I'm sorry, I'd have just as soon helped out somebody here, that's trying to help other folks, as I would've give the money to the dealership, I'll know for next time. I may drive over to the show and change it out there in the show grounds, we'll see. Sorry for the poor spelling in the last post, I was in a hurry. Thanks again for all of your help and I'll make sure and let ya know whats going on with it, if the sensor fixed the problem and kept it from throwing codes! talk to y'all soon...

 

Well, the part will be at the dealership today (Sat.), BUT no one will be there to take it in or sell it to me, they are all off till Tues., would've thought he could have told me that yesterday! Guesse the sensor, installation, and update will have to wait till then...

 

The rest of the story...... Well, the EBP sensor came in today, picked it up (to the tune of $147) got home, put 'er in and cleared the codes. Fired it up and all ran great, and NO CODES THROWN!! So a BIG THANK YOU goes out to F350-6 for taking the time to answer my questions, post pics, and help out in general!! Saved me a lot of money and I appreciate it. It took care of codes P0470 and P0478, in case anyone was curious as to what the problem was. Thanks again....