2004 F150 no cruise control and daughter is not happy.

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#1
Make
Ford
Model
F150 (not Heritage)
Year
2004
Miles
190,000
Engine
4.6L v8
Cruise control on this truck will not work. No codes stored in any module. Watched cruise control switch signals come into PCM with Forscan on laptop. All signals are what would be expected to seen in the PCM. No ABS codes or faults. No obvious wiring problems with anything that I would suspect prevent the cruise control from working. I have an alldatadiy subscription and have not been able to find any help besides what I have mentioned. I did install a new set of cruise control switches on the steering wheel because the resume button was sticking. This didn't help. This model does not have a servo for the cruise control. PCM sets speed by operating the electronic throttle. I replaced the throttle position sensor because I was watching the signals from the sensor to the PCM with Forscan and observed the TPS signal momentarily drop to zero and come back at low speed (roughly 20mph). This thing is going to drive me to drink more than I already do. Thanks in advance for your assistance. I have been lurking here for some time and you guys know what you are doing. You don't find that on other sites.
 

nickb2

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#2
This thing is going to drive me to drink more than I already do.
A daily battle for me.

Lurk on, we like that.

Only a few things can go wrong here, and I will do my sherlock holmes here.

So we know you are seeing switches @ PCM, hence we know steering switches are good, and by the fact you are seeing that with forscan on laptop, we also know the clockspring is good. So that leaves three things that can go wrong after that. Either the wiring, the range sensor on trans, or the PCM itself.

So even after a visual check of the wiring does not mean something is not open or short or a corroded pin etc.

Here is a pinpoint test, which you probably already have, but I uploaded it here anyways so you and me can follow at same time.

Start by checking the range sensor first. You should be able to also get PID data with forscan for that sensor also. Congrats by the way on acquiring that software and dongle. Very useful. I have not used this software yet, but I am downloading it as we speak, will try it at the shop today as I have a ford f350 camper to check out, will check what pids I can get with my elm327 BT.

Here is that pinpoint test "A". See ace 0 pdf.

I am off to work, hopefully, you will have had time to check some of this out, I will respond after work once I have gotten my six pack at the store. :cool:
 

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#3
Talking about manufacturers leaving off switches on basic models, no cruise control. TBW uses just one servo on the TB eliminating the need for the IAC and a servo for cruise, cheaper. Already have Vss and a pulse counter in the ECU that be be locked with the set button. and instead of looking at the gas pedal potentiometer that feeds through an A to D converter, looking at the preset number in the memory bank.

You do have a brake switch on the pedal to disable it, has to maintain contact for the cruise to operate, even on older systems, those contacts can be dirty. Outside of this, can only think of an ECU reflash. Really dumb storing code in erasable flashram, claim to be good for ten years. you are on 14. Broken clock spring is another possibility, watch out for that air bag.

Ha, even my Model A Ford had a form of cruise control, fixed lever on the steering wheel with a detent it. When you moved it, gas pedal would go down. With this new stuff, wondered if I could switch the potentiometer on the gas pedal to a fixed one and do the same thing, but getting too old to play around.
 
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#4
Thanks for all of the good info, gentlemen. Just so you know, I did observe the brake pedal signal on my Forscan program. I knew that this was one of the signals that could disable the cruise control. That appears to be working as it should. I am working nights at my regular job this week, so I probably won't be able to look at this again until Friday. At that time, I'm going to see if the transmission signals you have mentioned are getting to the PCM.

I wish things were as simple as they used to be. I drove both a '34 Ford truck and a "34 Chevy truck. They had the hand throttle on the dash. The cruise went out on my '94 Dodge diesel when I had it and I almost put a power take off hand throttle on it to take its place. It would've worked just fine because it had a manual tranny. My son ended up with it and used it when he went to diesel mechanic's school.

I'm an industrial electronics technician for my regular job so I have a good understanding of just how complex this stuff can get. I wish I had the type of equipment I have at work to look into the PCM. I can see the entire program for industrial machinery. Its too bad we can't do that with our cars.
 
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#5
Year after my youngest daughter graduated from college the car I gave her died, and I mean not worth repairing, so she purchased a 2015 model Soul. Ha, kind of mean, at this stage in their life, time to buy their own cars, I am done. Wanted $3,000.00 more just to get cruise.

Found the switch plate and harness on the net for $55, her dealer told her to go to some aftermarket place, and pay $740.00, put that in for her and in worked and was strictly OEM. Took about a half an hour, first time for me, and it worked, dash lit up when its on.

GM is even worse to add cruise for their base models, have to replace the entire steering wheel, and very difficult to find clock springs. Least $400.00, would be cheaper for GM just to install it in the first place, more tooling and more inventory, really darn right mean to people that can't afford a more expensive vehicle. But you do get AC, electric power steering, power windows, and a radio that lets you make hand free calls.

Just way to easy to get a speeding ticket today without it.
 

nickb2

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#6
Well, I did try the forscan software. Seems great for ford and mazda etc.

Problem is, it won't see my elm327 BT, however it does see my maxi flash elite j2534 BT reprogramming interface.

So after some research on my bosses dime.:eek: I found that a special elm327 is available for the forscan software which has a switch for the HS/MS can protocols. Screenshot (185).png So I will not be able to see what you see since I won't invest in a new elm right now, or probably ever again since I am buying my bosses old autel 908.

But from what I see on the forscan software, you should be able to see alot more than cheap apps such as torque pro, obd doctor and such.

Just the fact that it saw my j2534 means you can do PATS key reprogramming and more. Quite valuable for ford owners.

I kind of wondered why the PC version is free but you have to pay for the android version.

If the android version was free, I would be ordering a elm327 with switchable hs-ms as we speak as I like just taking my tablet and BT dongle wherever I go for quick diagnostics on the fly for my friends and family.

Anyway, with that flowchart I provided, which you probably can get with your alldata subscription, you should get joy out of that forscan software to find out if you do in fact have a PCM issue or just a range sensor or just a open/short wire somewhere.

Since you are a electronic technician, you and me should get right along.

I just fixed my sister radio amplifier in her lexus last weekend, Got to see my son, my mom too. Some idiot reversed jumped the battery, so I was able to get the lexus is 250 AWD car on the cheap as many modules blew out. It ended up being two 3amp 400v diodes that shorted. Got those for 49cents a piece, soldered them in and presto, metallica was blasting out of that sweet OEM pioneer amp. My sister was quite happy, she needs her tunes. The BT speaker I gave her, coupled with her smart phone was just not cutting it. It was funny hearing her rant and rave that I had to wait on those diodes. I told her to shut up, I found her a 12grand car for 7grand, so put up with it and shut up till I get up there to fix it. I have a life, and your tunes are the least of my worries with life and work going on. :cool:

It was an overall great weekend except for the six inches of snow in april that put a dent on things. Winter just does not want to go away this year. Global warming???? Not up here it ain't.

@ Diesel don, I know I am writing more than I should, but we could sure use an electrical technician here. So stay with us, we have use for guy's like you, and you never know, you may make internet buddies as I did here.

Great bunch of guy's, and no smoke usually blows out of our arses.
 
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#7
If your AT is shifting okay and your speedometer works, its not your Vss. Can also be a totally unrelated problem like low starting voltage, not getting a proper power on reset that may just affect about anything. Just hook up my digital scope, if the voltage after hitting the starter drops below 8.5 volts can be a connectivity problem.

Like that fellow that thought he needed a new MVAC system that would not switch on. low alternator output.
 
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#8
Thanks again for all of the replies. So, I guess I should start by addressing them. Nickb2, you are right about the dongle. I bought a BBFly from Amazon and it has the switch to select the two comm protocols you had mentioned. My Forscan works really great so far, but I have only touched the surface on its capabilities. As I have more time, I will play with it some more and try to use it to its full potential. The biggest problem I have now is time. Saturday starts the biggest outage my employer has had in 6 years. I won't be able to do much until after April 30th. I'm on 12 hour days until we get stated back up. I still plan on putzing with this on evenings if I'm home early enough. Unfortunately, 12 hours is the minimum. I foresee quite a few 16s in the mix, especially on startup.

NickD, that is exactly why I finally came here with this problem. I did replace the alternator about 2 weeks ago because it did quit charging. I verified that by looking at battery voltage after shut down and during engine run. 12.6 v off, 12.2v and falling after start after charging the battery with my charger. The cruise control was acting up long before that happened. I do have a brake warning light that has been on since I bought the truck. I thought that maybe it may cause the problem, but the cruise has worked with that alarm present before. I don't think the transmission range switch is bad because the transmission shifts and otherwise operates like it always did. I'm still going to see if the transmission gear selection is getting to the PCM. Now, as far as vehicle speed, there are 3 sensors that look at the vehicle, transfer case output, and converter speed. Maybe one of those sensors is not seeing the right signal and the PCM won't allow cruise. I didn't read that directly in Alldata, I just thought it was worth looking into because the throttle position and accelerator position each output 3 signals and if any one on each sensor fails, PCM assumes what that signal should be and won't allow cruise control operation. Not knowing exactly how the PCM program reads and interprets these signals makes this just a somewhat educated guess.

Voltages out of spec can create all kinds of havoc with any microprocessor controlled piece of equipment. Not only that, but what kind of fail safes are built into the equipment, and also what is written into the program. I had a very interesting and potentially dangerous problem at the mill last week where we had motors and valves operating by themselves without operator commands. A bad I/O card was the cause. It's damn scary when an electric motor starts with a ghost operator !!!!!
 
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#9
Received my BSEE from college professors that didn't know crap after serving six years in the USAF, was in a cold war back then and way ahead in technology and everyday was a 16 hour day, some were longer. Worked in automation for eight years, was in automotive and aviation electronics since 1972, retired in 2011.

Automotive is just about the most difficult, no test points, no voltages, no waveforms. Using the same processor that does the work to diagnose itself, everything else uses secondary references. Still read codes, does kind of narrow it down a little between the fuel evaporative or the emission systems.

Did take courses in microcontroller programing and was good at it, but one hour writing code on a computer was an eternity so specialized in mixed signal ASIC technology, one example of this is using logic from pulses from the CAS to fire the correct spark plug in a distributorless ignition system, no power on reset, no code to read one byte at a time. Day flew by. Actually the entire PCM can be done this way, but its short coming is a dedicated system, using an 89 cent microcontroller can be reprogrammed.

PROM's died in 1995, EEPROM's took over in 1996 with the advent of the internet for updating, but why updating, can't do it correct in the first place.

Another trend over the years, why all these separate modules, ignition, voltage regulator, AT, cruise, etc. Can you put allthis in one box to save all that cabling? A friends cruise went out in his VW, PCM was sealed tight, I couldn't help him, cost him $1,300.00 for a new one plus labor.
 

nickb2

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#10
Although this would be a first time for me seeing a cruise go out in the PCM on a ford such as this, I wouldn't rule it out. But I have swapped my fair share of transmission range sensors. I just briefly read through my ace o pdf, first thing they ask to do is check the range sensor to see if it is being seen by the pcm which Diesel don apparently can do with that sweet software. Next is checking the wiring, clockspring etc.

Although I hate ford as a product, I love how they give great flowcharts. Most companies don't include connector views in their flowcharts, have to look those up separate and print them out cuz I find it faster that way. But with ford, I just use my laptop as paper since I don't have to go back and forth from pin connector view to wiring etc.

Looks like don will have a great old time when he gets off shift with his laptop and multi-meter. But what wouldn't we do to keep our children happy. ;) Hah, If it was my son, I would be saying here is the flowchart, my laptop and meter. Learn.

My son needs to learn English, this is a great way to learn. Kids now days don't like getting their hands dirty. Local welding school had only two inscriptions for the next course. looks like we will need more immigrants to fill the gaps. Canada is good that way. But I think my government should focus more on incentives to put our own kids in school benches to fill the trades gap this is dwindling at an alarming rate.

We just hired a new girl apprentice at the shop. She sits down a lot and fusses with her phone all day. Doesn't pick up after herself, and judging by her car, that is not going to change soon. Hasn't bought any tools, and when we lend her some of ours, We find them in all kinds of places except our tool boxs, and oil on the floor wherever she passes. I have had numerous apprentices in my day under my wing, some of them girls, but this one is getting fast under my skin. I understand the job is dirty, does not mean we have to work in a pig sty all the same. I figures since she was on the phone all day, I would show her how to use the damn thing for actual car use with a spare elm327 I keep at work. She declined the offer, told me all she knows about electronics is netflix and facebook. I said to myself, man(girl), you are in the wrong trade.
 
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#11
I didn't get a chance to look at the truck. This shutdown here barely started and it's already nuts. I'll keep you posted as soon as I can get another look.
 
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#12
My daughter tells me that the truck stalled out on her the other day. I thought I had that fixed with the throttle position sensor. I saw the glitch on the signal with my ForScan program and thought I found the cause. Evidently, it wasn't the right solution. I need to dig into this again soon. I'm starting to think grounding problem or PCM has a glitch.