Dash Removal-Ongoing IVS Issue-Help!!!
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
I have removed a couple of these dashes, but it's been a while. As best I can recall, you pull the steering column (which is a lot easier than you might think). Then you take all the screws out that are up along the base of the windshield, take the bolts out of the big aluminum bracket on the driver side, there are 1 or 2 bolts in a couple of lateral braces underneath and 1 or 2 on the passenger side. Then it starts to come loose and you just have to unhook a few wiring, vacuum and cable connections behind the dash. It's really not all that bad as I recall. It took me a long time the first time, but the second time I did it I want to say it took me less than an hour to have it out.
You may want to trim out the insulation around where the big aluminum bracket bolts to the firewall, but aside from that I don't see why not. One thing I do recommend though is that you take 10 minutes before you start and remove the front seats. Having those out of the way makes this 10 times easier.
Post Fiend
Joined: Dec 2010
Posts: 10,121
Likes: 3
From: Orrville, Ohio
Before y ou start running new wires, I would test for voltage at the IVS when this happens. If you have voltage at neither wire, your issue is between the IVS and the fuse block. If you have voltage on one wire and not the other when the pedal is depressed, you have a bad IVS. If you have voltage at both wires when the pedal is depressed, then your issue is between the IVS and the PCM. It would at least give you a direction to start in.
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
Before y ou start running new wires, I would test for voltage at the IVS when this happens. If you have voltage at neither wire, your issue is between the IVS and the fuse block. If you have voltage on one wire and not the other when the pedal is depressed, you have a bad IVS. If you have voltage at both wires when the pedal is depressed, then your issue is between the IVS and the PCM. It would at least give you a direction to start in.
Lead Driver
Joined: Oct 2003
Posts: 8,476
Likes: 37
From: Madison, WI
If there _is_ voltage when you first check it, that brown wire is _probably_ good, and the red/orange wire from the switch to the PCM is probably the bad one. At that point, you'd want to do a continuity check (which would be tricky, would require some extension wire) between the red/orange wire terminal at the switch, and pin 5 at the PCM. Most likely it will show "open", infinite resistance, no continuity. Again, jiggle the wires and watch the meter, see if it eventually shows continuity / zero (or very low) resistance. That would implicate that that's the faulty wire.
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
True, but Nate's idea is to narrow down WHICH wire is bad. First thing to test would be the brown wire. Wait 'til "it happens", then put a voltmeter on the brown wire terminal at the switch. If no voltage, keep the meter on it and jiggle the wires as you've been doing. See if the voltmeter eventually responds and the CE light goes off at the same time. If so, that fingers the brown wire from the fuse box.
If there _is_ voltage when you first check it, that brown wire is _probably_ good, and the red/orange wire from the switch to the PCM is probably the bad one. At that point, you'd want to do a continuity check (which would be tricky, would require some extension wire) between the red/orange wire terminal at the switch, and pin 5 at the PCM. Most likely it will show "open", infinite resistance, no continuity. Again, jiggle the wires and watch the meter, see if it eventually shows continuity / zero (or very low) resistance. That would implicate that that's the faulty wire.
If there _is_ voltage when you first check it, that brown wire is _probably_ good, and the red/orange wire from the switch to the PCM is probably the bad one. At that point, you'd want to do a continuity check (which would be tricky, would require some extension wire) between the red/orange wire terminal at the switch, and pin 5 at the PCM. Most likely it will show "open", infinite resistance, no continuity. Again, jiggle the wires and watch the meter, see if it eventually shows continuity / zero (or very low) resistance. That would implicate that that's the faulty wire.
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
Well, I am going to be tackling this today. I am going to test the wires,but something is telling me it is the red/orange wire going to the PCM. The brown wire to the #3 fuse does not need to be touched. If I wiggle the R/O wire, I can get it to work. AS long as I leave it running, I have no problems. That also leads me to believe it is that wire because it acting like when you click the IVS one time to tell the PCM to open the throttle. Wiggling it makes it tell the PCM that the throttle is ready (my IVS is relocated under the dash). I hope this makes sense? I will verify this with my nice, new inexpensive volt meter. 
So, my next question, since I am believing that wire is the culprit, what happens when I unplug the PCM? It has to relearn all of the perimeters when I plug it back in, correct? What should I expect behavior-wise from the truck when I get it all back together, assuming the issue is fixed? Will it start and run? Will it shift normally? Do I have to drive it for a few miles to let it set itself?
So, my next question, since I am believing that wire is the culprit, what happens when I unplug the PCM? It has to relearn all of the perimeters when I plug it back in, correct? What should I expect behavior-wise from the truck when I get it all back together, assuming the issue is fixed? Will it start and run? Will it shift normally? Do I have to drive it for a few miles to let it set itself?
Posting Guru
Joined: Nov 2011
Posts: 1,664
Likes: 4
From: Southern AZ
Well, I am going to be tackling this today. I am going to test the wires,but something is telling me it is the red/orange wire going to the PCM. The brown wire to the #3 fuse does not need to be touched. If I wiggle the R/O wire, I can get it to work. AS long as I leave it running, I have no problems. That also leads me to believe it is that wire because it acting like when you click the IVS one time to tell the PCM to open the throttle. Wiggling it makes it tell the PCM that the throttle is ready (my IVS is relocated under the dash). I hope this makes sense? I will verify this with my nice, new inexpensive volt meter.
So, my next question, since I am believing that wire is the culprit, what happens when I unplug the PCM? It has to relearn all of the perimeters when I plug it back in, correct? What should I expect behavior-wise from the truck when I get it all back together, assuming the issue is fixed? Will it start and run? Will it shift normally? Do I have to drive it for a few miles to let it set itself?
So, my next question, since I am believing that wire is the culprit, what happens when I unplug the PCM? It has to relearn all of the perimeters when I plug it back in, correct? What should I expect behavior-wise from the truck when I get it all back together, assuming the issue is fixed? Will it start and run? Will it shift normally? Do I have to drive it for a few miles to let it set itself?
Richard
Post Fiend
Joined: Dec 2010
Posts: 10,121
Likes: 3
From: Orrville, Ohio
Well, I am going to be tackling this today. I am going to test the wires,but something is telling me it is the red/orange wire going to the PCM. The brown wire to the #3 fuse does not need to be touched. If I wiggle the R/O wire, I can get it to work. AS long as I leave it running, I have no problems. That also leads me to believe it is that wire because it acting like when you click the IVS one time to tell the PCM to open the throttle. Wiggling it makes it tell the PCM that the throttle is ready (my IVS is relocated under the dash). I hope this makes sense? I will verify this with my nice, new inexpensive volt meter.
So, my next question, since I am believing that wire is the culprit, what happens when I unplug the PCM? It has to relearn all of the perimeters when I plug it back in, correct? What should I expect behavior-wise from the truck when I get it all back together, assuming the issue is fixed? Will it start and run? Will it shift normally? Do I have to drive it for a few miles to let it set itself?
So, my next question, since I am believing that wire is the culprit, what happens when I unplug the PCM? It has to relearn all of the perimeters when I plug it back in, correct? What should I expect behavior-wise from the truck when I get it all back together, assuming the issue is fixed? Will it start and run? Will it shift normally? Do I have to drive it for a few miles to let it set itself?
What do you mean the IVS is relocated?
And yeah, what Richard said. The only thing the PCM "learns" is supposedly what rear end ratio you have, and even that is up for debate. The PCM really suffers no ill effects from being unhooked.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
Got it. Thanks!
Nate, I don't know if you remember, but I relocated the IVS under my dash and it fixed the jumpy throttle. I did it back when i was having major issues with the TPS and dead throttle. Rather than try the pedal mod and bending the tab, I read another thread where it was removed from the pedal and relocated under the dash or wherever one wants to put it. Throttle is WAY smoother. You have to click it once, after starting the truck, to tell the PCM to engage throttle from the TPS. I can put it back on the pedal if needed, but that isn't an issue and has been much more driver friendly.
See here if you have time:
https://www.ford-trucks.com/forums/1...-question.html
Thanks Glenn! helps quite a bit!
See here if you have time:
https://www.ford-trucks.com/forums/1...-question.html
Thanks Glenn! helps quite a bit!
Post Fiend
Joined: Dec 2010
Posts: 10,121
Likes: 3
From: Orrville, Ohio
Got it. Thanks!
Nate, I don't know if you remember, but I relocated the IVS under my dash and it fixed the jumpy throttle. I did it back when i was having major issues with the TPS and dead throttle. Rather than try the pedal mod and bending the tab, I read another thread where it was removed from the pedal and relocated under the dash or wherever one wants to put it. Throttle is WAY smoother. You have to click it once, after starting the truck, to tell the PCM to engage throttle from the TPS. I can put it back on the pedal if needed, but that isn't an issue and has been much more driver friendly.
See here if you have time:
https://www.ford-trucks.com/forums/1...-question.html
Thanks Glenn! helps quite a bit!
Nate, I don't know if you remember, but I relocated the IVS under my dash and it fixed the jumpy throttle. I did it back when i was having major issues with the TPS and dead throttle. Rather than try the pedal mod and bending the tab, I read another thread where it was removed from the pedal and relocated under the dash or wherever one wants to put it. Throttle is WAY smoother. You have to click it once, after starting the truck, to tell the PCM to engage throttle from the TPS. I can put it back on the pedal if needed, but that isn't an issue and has been much more driver friendly.
See here if you have time:
https://www.ford-trucks.com/forums/1...-question.html
Thanks Glenn! helps quite a bit!
Lead Driver
Joined: Oct 2003
Posts: 8,476
Likes: 37
From: Madison, WI
Now that you've identified the IVS issue as a wiring issue, when you get it resolved, it would be a good idea to repatriate it back to the pedal, where it was designed to operate. But cross that bridge when you get to it.... (crossing fingers that your wiring fix works...)
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
Now that you've identified the IVS issue as a wiring issue, when you get it resolved, it would be a good idea to repatriate it back to the pedal, where it was designed to operate. But cross that bridge when you get to it.... (crossing fingers that your wiring fix works...)
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
Ok, I must be pretty dumb. I am not getting this testing at all. When I test my batteries just to make sure I am getting a good reading, I am getting 27 on the LED screen on my meter. When I test the brown wire at the pigtail, I get a reading of 27 with pedal depressed or idle. I have not tested the R/O yet. I have to get to the pin to do so. I am such a rookie at this electrical stuff. Continuity versus ohms versus voltages is making my all crazy. Any help or direction would be so appreciated. I did do what was described to me to do, but just got the reading of 27.
Thread Starter
|
Hotshot
Joined: Mar 2012
Posts: 10,590
Likes: 382
From: Texas
Ok, now I am seriously confused. There are 3 wiring harness on the drivers side firewall, but only 2 under the dash! What I thought was the PCM I am not even sure about now. The harness on the FW closest to the outside looks to be the PCM, but where does it come into the truck under the dash? I would post a photo, but I am not at home yet.