Chasing my tail on a TPS issue

thatguy69

thatguy69

New member
So ever since I converted my truck over from a fmvb to a regular auto vb(2016) I've been chasing this TPS problem. Here's the issue,when at idle I can watch the TPS number on both my edge,and anteater pro jump sporadically like this 0,10,0,15,0,0,0,0,12,0. When driving,average pedal position is 25-30% so the readout on the edge/anteater will bounce 10-15 numbers higher than actual pedal position which really screws with my shift tables as you can imagine. Something similar to 25,30,25,40,25,45,30,25,45 etc when holding the pedal steady. It always bounces higher though,never lower than the actual pedal position. With the engine off and key on power the TPS percentage stays at 0 with no bouncing like it should.so far I have tried the following,new timbo apps,TPS wire reroute,cleaned all grounds and connections. Battery connections are new and clean.checked alternator for ac noise,which it passed with flying colors,and I even ran with the alternator disconnected from the batteries. Joe farmer has also buffered the TPS signal in the anteater software as much as possible which did help but it's still makes the truck a nag to drive. My only other thought's are swapping out my ecm but those aren't exactly easy to get your hands on,I'm all ears fellas. Next step is to throw a match at this thing if I cant come up with something :bang
 
You could try putting a small capacitor from the TPS input on the anteater to ground, I had a similar problem with the TPS signal on my BOV controller. Set it up when the trucks off and everything is happy, start the truck and go for a drive then it starts venting under acceleration. After putting a scope on the TPS line it was clear how much more noise was present with the truck running.
 
Are you using the ECM 5V supply or anteater 5V to power the TPS?

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zachu812 said:
You could try putting a small capacitor from the TPS input on the anteater to ground, I had a similar problem with the TPS signal on my BOV controller. Set it up when the trucks off and everything is happy, start the truck and go for a drive then it starts venting under acceleration. After putting a scope on the TPS line it was clear how much more noise was present with the truck running.
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I'll see what I can scrounge up, thanks
 
Gotta' ask.
Does it affect driveability, or is it because you can "see" fluctuations, that it bothers you?

You'll hate me for my next suggestion.

Try swapping ECMs, if not that, then pump/module.

Mark.
 
Mark Nixon said:
Gotta' ask.
Does it affect driveability, or is it because you can "see" fluctuations, that it bothers you?

You'll hate me for my next suggestion.

Try swapping ECMs, if not that, then pump/module.

Mark.
Click to expand...
Yes it effects driveability. It'll randomly downshift when just cruising in town because it thinks I floored the pedal to 50 percent even though I'm really holding it at 30 percent. It also messes with the regular upshift points from time to time. Like when towing and shifting on the 2-3 shift it'll bounce 2323 which isn't only annoying as f with 21k behind you but I know it's gotta be hard on the Trans. Yeah both of your suggestions suck lol, I have an 01 I can swap parts off of but I don't think I can swap the ECM because of the different cps correct?
 
No, 2001 is definitely different, but there are folks who can flash the modules for your year combo.
Are you still tied into the pcm on the firewall?
I wouldn't discount it causing an issue, either.
It is also a primary part of controlling the transmission, after all.

Mark.
 
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Mark Nixon said:
No, 2001 is definitely different, but there are folks who can flash the modules for your year combo.
Are you still tied into the pcm on the firewall?
I wouldn't discount it causing an issue, either.
It is also a primary part of controlling the transmission, after all.

Mark.
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Yes still tied into the pcm on the firewall. What would happen if I disconnected the TPS feedback going to the pcm just to rule it out? Since I'm using the anteater I don't need the pcm to control the trans, and I think the feedback goes from the apps, to the ECM, and then over to the pcm. Trying to think of what functions I'd lose, just spit balling here.
 
The pcm should have a pretty large input resistance on that circuit, they're likely using >100k pull down resistor to ground which means it should have little effect on the signal, you can measure that to verify if you disconnect the signal wire. I'd try a $0.50 capacitor before you start thinking about swapping ecms.
 
For inquiring minds, I installed a 50uF capacitor from the anteater TPS signal wire to ground like Zachu812 recommended and my TPS numbers are extremely steady now. Hauled a load of I beams 100 miles round trip today, through towns with lots of stop and go and never had 1 issue. Thanks a lot Zachu812
 
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