APP & IVS Signal Dropping Out - P0122 & P0221 - Ford Powerstroke Diesel Forum
LinkBack Thread Tools Display Modes
post #1 of 2 Old 03-25-2011, 06:52 AM Thread Starter Rookie
Join Date: Mar 2011
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
APP & IVS Signal Dropping Out - P0122 & P0221

I posted this in the Excursion Forum as well, but since this is a 7.3L problem in general, I thought I would post it here as well since this forum folder gets more traffic. I hope this is ok, if not I can delete one of em.

Well, I am here to bring another APP & IVS issue to the table. I have done all the searching I could on the net and studied diagrams and trouble trees to best understand the problem I have. I am hoping that someone out there has experienced this very problem I am having so I dont have to do more investigative work (AKA: Vehicle dismantling) than I have to do.

Ok here goes:
Working on a 2000 Ford Excursion 4WD w/ 7.3L (170k Miles)
This is a friends Excursion I'm looking at for him. His wife complains of pedal drop out 1-2 times a day (resulting in engine return to idle). She says "About 10 seconds or so & it comes back on." I have retrieved codes P0221 & P0122 from memory. Cleared codes and have driven it for the past week while monitoring the AP & IVS Pids on scanner, I can NOT get it to duplicate. I dont know her driving habits, but I have been driving the vehicle "normally" since diesel is over $4 a gallon currently.
APP was replaced less than a year ago. From my research and testing so far on the vehicle, I have gathered that when you manually set a P0221 by interupting the IVS signal, it will not set a P0122 at the same time. Like wise, if you manually disrupt the APP sensor circuit and set a P0122, this failure will not set a P0221 as a result. Basically, these 2 codes will not set as a result of a single failure of either sensor (from my experience & testing anyway), both sensor circuits have to experience a failure to set both of these codes. My thought on this issue is that I may have a bad spot in the wiring harness where these two wires are intermitantly finding a various path (i.e.: shorting out to each other, a ground spot on the frame, etc.) They do not share the same power sources, or the same ground sources. They do however share the same wiring loom path from the accelorator pedal back to the bulkhead under the dash, same bulk head connector thru firewall, and same wiring loom path from firewall bulk head connector to PCM.

Before I go ripping into this thing, has anyone experienced this same problem with an Excursion before? I am hoping for something like "Under the dash about 1' in on the harness is a known wear point, check there." LOL, I know wishful thinking.

I did read one bulletin posting regarding a chafing spot on the Driver Side Shock tower, but initial inspection didnt expose any solid findings.
MB66 is offline  
Sponsored Links
post #2 of 2 Old 02-22-2015, 05:10 PM Rookie
Join Date: Feb 2015
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Did you find out your problem and if so could please reply. I have been dealing with this for over a year. Thank
smanley is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome