So pirshwagon, If I understand correctly, And please advise me if I misunderstood your post. YOU made a mistake by dropping a relay or a wire (sounds like it was "hot") and it fried the PCM? BUT, The "design" your pestering neighbor begged you to install for him & you reluctantly did install worked "great". Sure wish you would have posted some of the details of the design of the thing rather than the emphasis on "WARNING" because You made a mistake on a "works great" design. Obviously you have the knowledge of how these systems work (possibly read my long winded thread) but instead of addressing ANY of the questions posed or commenting on the correctness (or not) of the schematics I linked to....All you are saying is "WARNING" as if any DIY design is something to be scoffed at or not attempted because why?
Your bad experience with a great working design that YOU made bad by YOUR mistake by working on it with live / active wires or relays hanging down?

Jaythe CPA:...I looked myself. Seemed $300 plus was the lowest price I could find for an OEM Ford AIC and that was the more basic one of the two offered. You can also get one from some guy/company called dFuser for $79.00. But that's not the OEM type unit and I would HIGHLY SUGGEST you read his instructions that are available in a PDF download. The first page (or less), tells you how to (plug it in). The rest of the page & all of the 2nd page is LEGAL DISCLAIMERS! Bring that page to a lawyer friend and have him explain just what each of those seemingly innocent sentences means in legal terms.
Then, tell me why I should send $79.00 to someone for an AIC control that should I plug it in and it FRIES my PCM is going to send me exactly ZERO DOLLARS in compensation? Even if it's not (his) fault & his design is good, (maybe the thing took a hard hit in the shipping through the mail... HE is still exactly ZERO responsible for any of my loss due to installing HIS AIC unit!
MY post here is in searching for KNOWLEDGEABLE guys with a CAN DO attitude on DIY, AIC designs. LIKE MINE! I'm NOT here trying to sell ANYTHING and if I do ever get the answers I need & hook up MY DESIGN , I will FREELY distribute the schematics and information of the final WORKING product as well as answer & help anyone else that is interested in doing it the same way. And I will NOT feel any need to include any "legal language" to indemnify myself if someone drops a hot terminal relay or wire and fries their PCM or their whole truck. At some point (we) need to stop handing over every aspect of our lives to dirtbag lawyers and take on a little responsibility of our own. Printing (how to) and (DIY) instructions about things like this on the internet does NOT make you responsible for someone ELSE messing up! I went through this same nonsense trying to get information about my current DIY (myself) Cruise Control addition to my Van. Everyone so frightened to give any advice out of fear that if you don't pay some STEALERSHIP $1700 to "do it right", Then somehow THEY are at risk of a lawsuit. GEEEEEEEEEEZZZZZZZZZZZZZ.
Guess what.....I don't have the secondary high pressure shut off switch on my Master Cylinder to disengage the CC! I have two wires twisted together with a wire nut & some black tape. I was not about to spend (who knows how much) to R&R the Master cylinder (as the dealer would have INSISTED be done) just for some 1 & a million chance that tapping the brake pedal didn't disengage the CC. That was a $65.00 dollar job with a used steering wheel from the wrecking yard and lots of time asking questions & studying what has worked for people and what didn't.
Imagine , $1700 for some scumbag dealership to mess around with MY truck!
Worse than that, The first two I went and asked about adding CC to my van just said (guessed)....."I'm pretty sure it can't be done" !!!!! That's why I am a DIY minded guy! So if there are other DIY type guys on this forum I respectfully invite you to take a look back at my previous posts and check out the link to the schematics.
I am looking for the information requested in the post on this thread (#13 above) and I have no doubt that any DIY minded guys will understand what I am showing and the other questions I will want to ask about.
Sorry for the long posts but the 5 line (comments) are not what it takes to have detailed question & answer sessions to get good comprehensive answers to do stuff like this. Please, No Negative Nancy's or Buy the one from the "aftermarket guy" people. They are usually the ones running the aftermarket parts stores on line in different names. Yeah, I know the game. Scroll through all the sites and put up posts that lead you to THEIR product or try to SCARE you off from doing it yourself.
Same thing with the CCV Mod. God forbid you just disconnect it and block the hole in the intake. You need to buy some special catch can kit, HOSES, mounting bracket, and clamps and everything you need to (fix) the OEM design. All for just $299.99!
OTHERWISE, your going to OVER PRESSURIZE your Crank Case and start blowing out major seals and having big oil leak problems. OR WORSE!!!! GEZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ DDT

 

That's the way I took his post. I'm sure it wasn't a nay-saying slight towards the mod, but one thing most folks on FTE are good about is WARNING people if a particular mod OR procedure has a significant risk of damage- especially something like a PCM.

Many (most?) of our members are comfortable with basic mechanical or even electrical manipulations, because even without a background or a lot of experience in an area, the amount of support and rapid replies when someone gets "stuck" on a problem or with a problem is very good.

Back to the mod....

WELCOME TO FTE!!! Glad you joined and even better, you're already contributing a pretty cool mod

Diagrams and pics help a lot, too.

I already have a high idle tune in my Hydra, but am always interested in learning about other mods. Who knows, I might want use that slot for another tune!

...my remote start has an Aux trigger option. Would be nice to have that on cold mornings if I forget to set the tune to my high idle the night before and use the remote start...Hmmm

 

Haha. Yeah, I feel the same way about some of the "kits" out there. They start out with $50, but two years later, $250. MANY of the aftermarket things I look at now have DOUBLED in price since they were introduced

T500's were $250, now $450. That's one I was looking at recently.

Billet intake plenums just went up again this fall. But these are things I can't make on my own.

I think I'm in fair amount of company saying I like to do mods and DIY to my truck and see that look from people when they are intimidated by the fuel door on their cars, LOL

Anyways, keep up the contributions and keep it light hearted, we're a pretty laid back group. I find it refreshing myself

 

What you can take away from my post:

1. The instructions were flawless. To include the idle disengaging when the Brake Pedal is depressed or the Parking Brake was in the off position (Multi Relay Diode Circuit), very basic design.

2. It used either a Potentiometer (adjust the for PTO) or switch for immediate idling (which I did not mention as it was irrelevant to my warning).

3. There was nothing wrong with the instructions. Furthermore, they suggested assembling everything prior to permanent mounting for functionality inspection so corrections could be made.

4. This was totally my fault. If there is anything I learned over 30 years working on these is: DON'T HAVE THE KEY IN THE IGNITION WHEN WORKING ON THE 5v REFERENCE CIRCUIT. I failed my own rule.

5. It would do you well to learn from my mistakes (and others), rather than beginning your own list. Unless of course you want to make your own list.

 

I apologize if my post was (harsh) sounding. I am just trying to get specific answers to questions about
exactly how the Throttle system works so that I might finally see through installing my DIY AIC design.
I certainly appreciate (warnings). And again a line is written in the response by pirschwagon that
seems a bit unclear.
I Don’t mean this a s picking on pirschwagon! I maybe just read things to closely. He (you) say….” Don’t
have the key in the ignition when working on the 5 volt reference circuit”

I’m going to (guess) you mean (don’t have the key in the ignition and turned to the ON or ACCESSORY
position).

I seem to be having a problem in eliciting information from people about SPECIFIC questions about my
specific plan of action, and if there is anything they see inherently wrong with it.
I am new here so I have not really had the time (though I am sure it is simple once you do it) to figure
out how to post photos. So I just linked to the photos I have already posted on the other site/thread.

Maybe I should just start asking blind questions here……
1. Does anyone know if it is indeed 5 volts that is fed to the TPS on a 2003, 7.3 PSD, E-350? If so,
Does anyone know which wire is the 5 volt INPUT? (color code?).
2. How about the OUTPUT wire (color code)?
3. Is the third wire just a ground for what I assume the TPS is - a TRUE potentiometer?

4. Does the coil’s (ground side) of the 3 wire TPS go back to
pin # (?) of the PCM, And if so does the PCM just supply a
ground or does the PCM need to “read” some particular voltage
from that wire also.
5. I assume when we talk about a “return signal” wire to the PCM we are talking about the 3rd wire
from the TPS (not the ground mentioned above) that would be referred to as a “wiper” (technically
speaking in potentiometer terms)?

Essentially what I am getting at here is if one is careful, Can they do some (experimenting) ONLY AFTER
knowing, locating and identifying all three wires to the TPS, by redirecting the 5 volt supply from the
PCM through your own pots. (via a relay) & (presumably of a close enough resistance value) to
produce “return signal” voltage values in a similar range to what the PCM wants to see & WOULD see if
the voltage was still going through the TPS?
From the charts I have seen that could be anywhere between
Open Circuit (ZERO VOLTS) & 4.4875 for WOT. Obviously we don’t want our pots. To allow the 4.4875
volts through for a “return signal” as this would send our RPM to their Maximum value of ? (2300)? We
are only looking to the value between
0 and maybe 0.8875 volts.
Which brings up the next IMPORTANT question…..
6. Does anyone know if IDLE or TPS or Throttle pedal in it’s furthest back position creates an OPEN
CIRCUIT or ZERO VOLTS return to the PCM? (The chart I have seen for RPM / voltage values shows
“text” of “open circuit” up on the top level just before starting out with the lowest RPM & voltage
values.
The problem is…..It does not “line up” properly on the chart rows & columns to make it appear to be
giving that exact information.
It very well might just be a chart (lay-out) flaw, BUT it is very important information to know before
anyone starts (experimenting).
7. IF….I say again…IF one were to do some very careful (experimenting), Is there any reason to think
that if you tap into the 5 volt PCM supplied / limited voltage, and REDIRECTED it through your own
pots. And back through to the RETURN wire to the PCM…. Is there any reason to believe doing so
would “fry” your PCM? (I’m not talking about accidents here like picking up a 12 volt supply line voltage
OR dropping a bare wire that is in the circuit to the return to the PCM causing a short to a ground…).

I am talking about (experimenting) with a cut and redirected through YOUR pots. PCM supplied 5 volts.
???
There is no reason to think the PCM would receive anything other than between zero to 5 volts (or
some variable below 5 volt value) as you “experiment” with your adjustable pots. Roll *****???

Would not at worst case the PCM just sense some erratic voltage on the “return line” and likely throw a
code? Not “fry” the PCM?

I also wonder if there might be some micro second of time between the TPS & IVS , that each must
change voltage returns to the PCM within for the throttle to work?

Understanding that the IVS seems to be nothing more than a 12 volt on/off return signal to the PCM
and that IDLE is the OFF (no volts) returned to the PCM for that switch, and as mentioned above, It
seems like the TPS may also (start out) as a No volts, (or as the chart seemed to suggest “open
circuit”) for IDLE. I wonder if as the throttle pedal is pushed there is some “micro second” of time that
BOTH the IVS & TPS must begin to send voltage signals to the PCM on pins # (?) for the throttle to
respond?

That’s about all the questions I can think to ask before (I) want to go cutting into my TPS and
redirecting the wires through my chosen potentiometers & back to the PCM through a circuit OTHER
than the TPS.
I have made it all sound very complicated here BUT that is also sort of what I am trying to ask. With a
very basic understanding of things electrical, I don’t think the TPS, IVS operating system has some
(unknown to me) much more complicated thing going on.

It’s 2 return signals to the PCM…..One 12 volt (the IVS) to pin (?).
And one Variable voltage (NOT MORE than 5 volts)(the TPS) to pin (?).
Possibly a “requirement” that the PCM sees those voltage returns within (?) micro-seconds of each
other.
?????????????????????????????????????????????????? ????????????????????????????????????????????
?????????????????????????????????????????????????? ????????????????????????????????????????????
???????????????????????????? DDT

 

Which linear potentiometer one do I need 5k or 2 k 95 obs 7.3




QUOTE=ForemanES;4192504]These are instructions for the obs, it might work for yours

AuxiliaryIdleController

AIC MOD

by Sparky
Ok to start off with you will have to go to Radio Shack or similar store and get some parts.

Single Pole Single Throw Switch. Radio Shack pt# 275-612
5K Linear Taper Potentiometer. Radio Shack pt# 271-1714
Linear PART # for the 2K is Radio Shack pt# 900-8587
2 Single Pole Double Throw Auto Relays Radio Shack pt# 900-2391
2 Wiring Harness Plugs Radio Shack pt# 900-2396
18 Gauge Wire
SOLDER
Wire Ties
Butt Connectors
Soldering Gun
Safety Glasses

STEP 1 Switches

Find a power source that is with the key.
Run a wire from there to one side of the switch.
From the other side of the switch run a wire to the coil terminal of both relays
From the other side coil terminals on the relays run a wire to the parking break switch wire. (There is only one wire on the parking brake.)

STEP 2 Idle Validation Switch (IVS)

As you look at the throttle pedal you will see a switch on the left side with 2 wires going to it. The wires are taped together carefully un-tape them so you can work with the wires. I used a razor knife to cut the tape, but be careful not to cut the wires. (There should be a red/orange with and a brown wire, unless they changed the color code of these wires.)

Cut the red/orange wire leaving plenty on the switch side so that you can splice onto it. The red/orange wire that is going into the wire bundle needs to get hooked to the common side of one of the relays.

The other red/orange (the one attached to the IVS) goes to the NORMALLY CLOSED CONTACT (NC) of the relay. Now take a wire from the NORMALLY OPEN CONTACT (NO) and run it over to the brown wire by the IVS, you will just tap onto this wire so you don’t need to cut it. Just take some of the insulation off and solder it on, then tape her back up.

STEP 3 The other Relay and the Throttle Position Sensor (TPS)

Throttle Position Sensor (TPS) is located on top of the pedal and has 3 wires going to it. Remove the tape to expose the wires. (There should be a brown/white wire and a gray/white wire.)

Cut the brown/white wire, leaving enough to work with by the switch. Hook the end up that goes back into the wire bundle to the common side of the other relay.

Take the side that goes to the switch and hook it to the NORMALLY CLOSED CONTACT (NC) of the relay.

Take a wire from the NORMALLY OPEN CONTACT (NO) of the relay and go to the left terminal on the POT.

Now take a wire from the center terminal of the POT and tap it into the gray/white wire.

Tape up all the bare wires and enjoy[/QUOTE]

 

Holy ****! Just buy a chip with a high idle position and quit trying ro reinvent the wheel. Few people will be any help because nobody wants to risk damaging something due to cost of replacement of hard-to-find parts.

High idle calibrations can be had in many flavors and can be programmed to be delayed, have backpressure valve magic applied, a dead pedal, et al.

 

I can see where Mark is coming from as there is a degree of satisfaction in completing a project such as this on your own and seeing it from cradle to grave.

Although, I agree with Cleatus that it would be much easier and safer to buy a chip, which is what I did.

 

Well DDT,

Instead of asking others for answers, you could use your Digital multimeter to monitor the voltage of the Throttle Position module wiring yourself. That way you are not relying on others for information that may or may not match your truck. In a nutshell, you want to disconnect certain wires from the actual pedal and reconnect them over to the device that you are building. In the electrical trade we call that a transfer switch, when it is used to connect a generator or other alternate device (of which there are many).

That is why you can easily duplicate the actions of the throttle position sensor by wiring up a duplicate circuit, using a pot and a relay. The Idle confirmation is something you can play with separately, because that is a separate circuit. If you are determined enough, and research the needed basic electrical knowledge to understand how to make this work, you will be successful.

Considering the expense of replacing a failed PCM, you should proceed on your own rather than asking others to chime in. That way, if something goes wrong, it is on you only.
Larry

 

hey foremanES great info!! People like you make the world go round!! Do you have the link for the website you mentioned above the old link won't work thanks in advance!

 

@MitchellDavid I am sorry to say "ForemanES" hasn't been active on the FTE since 2016.


I attempted to dissect the link provided by ForemanES, but even the source URL of "prodigy.net" does not appear to be valid any longer. Although, a good deal of us active FTE'rs have access to the wiring diagrams created by Ford so many years ago. We have the details for each connector, pin and wire color you could ever desire when related to the 99-03 7.3L.

So, if you have a question or concern, please voice it here and we will see if we can help you set a course of action toward success.

 

@MitchellDavid I have a manual high idle control you can have for the price of postage.

 

Reps sent for the generous offer Leonard! You have been there time and time again for many of us, myself included and we appreciate your detail, kindness and generosity toward the FTE community.

 

Top 10 of FTE greatest comic responses, a true classic!

 

https://www.thedieselstop.com/threads/steve-bazs-info.658221/