BryanD

but, as stated before, there doesn't appear to be a practical way to recalibrate Pedals/TAC's to the ECM.

FRUSTRATED!

wayneosan

http://forum.ih8mud.com/80-series-te...-begins-9.html


This is my swap. Look at the scope trace of a faulty TAC module. I don't have a scope posted but ill get one if everyone is interested. I have two (thanks jeff) pedals and three modules here. Through all my testing I just noticed that the range of voltage is different between the two. If I remember correctly. Id like to just log voltage of the pedal on the scope and drop in a resistor on both sensors in the pedal to bring down the voltage. The pcm seemed to not care where "low" was and just took the lowest voltage it saw as 0% throttle during that particular key cycle. More on this later. What do you guys think?

wayneosan

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Jim_PA

iTrader: (8)

I'm not nearly as well versed in the voltages and specifications as you are, but what I can prove, is that when I take the pedal out of my swap truck over to my 2004 GMC Yukon, the "swap" pedal behaves the same way on the Yukon as it does in my 68 C10.

I have ordered and installed 2 different APP sensors into my swap pedal, and confirmed that both on the swap truck, and in the factory truck, nothing changes.

I know it will sound like I'm beating a dead horse, but I swear that if I could manage to get the electronic adjustable gas pedal (EAP) out of my Yukon, and plug it into my swap truck that everything would work normally in my swap truck.

Although several have said that they got all the parts (PCM, TAC, pedal, wiring) all from the same truck and have indeed experienced this phenomenon, something doesn't add up. Is there a hidden 5v reference (or some other trigger) to the EAP switch that tells the PCM that electronic adjustable pedals are (or are not) installed, and it comunicates this to the PCM somehow??? I have no idea, but as crazy as it sounds, I ran out of logical explanations a while ago

Maybe I should go out and take the door panel apart in my '04 Yukon and disconnect the EAP in/out switch and see if the pedal range of motion changes.

BryanD

have you guys seen this in HP Tuners? i think it is a new feature of the Beta version that is being shipped, and what i have. My friend with the previous version does not have this tab.

it appears to be a way to recalibrate or adjust the TAC / ETC but here is the "kicker". every table is followed at the bottom of the window by the following corresponding message:

Throttle Max Rotation % vs. Pedal: Max throttle rotation in relation to pedal. WARNING!!! Modify this table at OWN RISK. Incompatibility of this calibration with the vehicle TAC module calibration may render PCM permanently inoperable.

i've been dying to play with the tables to solve the 50% pedal - 100% throttle problem but i'm affraid to. kinda interesting why they even give you this tab.

Jim_PA

iTrader: (8)

Yes, and I've messed with it to help with tip-in sensitivity.

The problem is that the computer and the TAC/Pedal don't agree on where 100% WOT is, so that table isn't going to fix it.

wayneosan

I think that's in beta only..? I have EFI LIVE and HP Tuners. I'm going in early today to look in the programs.


ok at work now: I looked in my files and in EFI Live, which I tuned my truck on, I don't see a throttle calibration for my OS. I don't have my tune in HP tuners, but I might go license it in HP tuners to mess with the throttle settings, although, I believe like the previous post, this is not the issue. Has anybody posted on the EFI LIve or HP tuners forums to see what kind of response you get? If not, I'll gladly link back to this thread and ask around.

Wayne @ T1

BryanD

Jim_PA, so any changes to those tables didn't "brick" the ECM?

also, guys. i found this the other day, but haven't messed with it either:
in the HP Scanner; Displays/VCM Controls/Trans tab there is a button on the lower right hand corner that says "Pedal Pos Relearn". Anybody mess with this yet?

Jim_PA

iTrader: (8)

Well, the changes I made didn't brick mine I think I copied the table out of a 2006 file that had less slope in the lower pedal position areas.

Never heard of the Pedal Pos Relearn. I think it has to do with idle though. Let us know if you find out what it means!

BryanD

with the few motors that i've done that had this problem i just welded a stop on the pedal at the 50% spot. i hooked the scanner to the motor and monitored TPS. when at 100% i welded the stop on the pedal. funny thing is, some OEM pedals actually have the 50% throw as there full motion. so basically some pedals actually move 50% more than others, so whats the difference on welding the stop on - problem solved IMO!