TPS1 and TPS2 disagree...P2135...need some help getting data for baseline

Tech discussions on the L77 6.0L V8.
Post Reply
rcodea1
Posts: 21
Joined: Fri Jun 07, 2019 5:58 pm

TPS1 and TPS2 disagree...P2135...need some help getting data for baseline

Post by rcodea1 » Tue Feb 18, 2020 3:27 am

All,

Could use some help diagnosing an issue with my 14 L77 setup. I have a few variables which all seem to be working properly, but the combination isnt. At this time i can not keep up with traffic as the code and reduced power mode happen when accelerating I have correlated this to be when at about 85KPA, though that may not be relevant. A Log of this happening is attached.

If possible, could someone please log their TPS1 and TPS2 voltages and % using the pedal? attached are the values i am getting now, which i think is causing the reduced power mode and dead pedal with a P2135 code and the occasional P0222.

Basically, I am getting huge differences with the TPS1 and TSP2. Using the pedal at 0%, i am getting TSP1 ~21%/3.51V and TPS2 8%/1.45V. At WOT, that changes to TPS1 68%/1.9V and TPS2 26%/3.04V. When i manipulate the throttle by hand, they agree at 0% with TPS1 4.31V, TPS2 0.65V when closed, and WOT at TPS1 99.6%/0.57V and TPS2 at 41%/4.39V. The log is attached as is the tune i am using.

I also used the attached P2135 troubleshooting pdf which has passed all the steps, which means the TB needs to be replaced. I have two more ACDelco TBs coming in tomorrow and will use them to troubleshoot, but i am guessing that this will not solve it.

Something else i have noticed, though it may not be relevant, is that the throttle position doesnt seem to match the PIDs/signals available. I circled the ones below which i am referring to. It is supposed to be following the Absolute Throttle, but doesnt seem to correlate properly. I even get some weird noise/oscillation in the signal as well which clears up in the log.

The variables in this system though....
1. '14 L77 using a 2bar custom OS from the hptuners, which has not been tuned yet....this may be causing the huge disagree with % throttle even though the voltages are reasonable, but i have no way to confirm this. I am hoping that someone can offer up their TPS1/2 % and voltage for comparison
2. the throttle pedal is a truck part number, done because of the harness i am using. I have the original pedal and plug, but am not convinced this is the issue as it is recognizing the 0-100% throttle positions correctly.
3. the truck has not been tuned yet...though i am not aware of this being able to fix something like this
4. i have tested already with 2 different TBs, and they are within 0.02V on both extremes...so either have two bad TBs, or something else is going on.
5. I am running a dual TB setup, which is being driven by a X2D unit from TorqueRush....but i have the same data as above with the unit plugged in and not connected at all. I do not think the X2D is the issue here....it is a 'invisible piggyback' on the system and I cannot see any data differences
6. I can get a clone e38, but will have to reflash it again and use some credits, so thats a $350 non-refundable troubleshooting device...not sure i am ready to go there.

happy to provide any further information which may be relevant....at this point i feel like i am spinning my wheels trying to figure this out.

Thanks in advance!

~Ryan
Charleston, SC
Attachments
Orange Peel Throttle issues.zip
(1.78 MiB) Downloaded 117 times
pedal 99%.jpg
pedal 99%.jpg (627.27 KiB) Viewed 1829 times
pedal 0%.jpg
pedal 0%.jpg (628.22 KiB) Viewed 1829 times
open.jpg
open.jpg (622.08 KiB) Viewed 1829 times
neutral.jpg
neutral.jpg (620.96 KiB) Viewed 1829 times
closed.jpg
closed.jpg (613.34 KiB) Viewed 1829 times
~Ryan
Charleston, SC

rcodea1
Posts: 21
Joined: Fri Jun 07, 2019 5:58 pm

Re: TPS1 and TPS2 disagree...P2135...need some help getting data for baseline

Post by rcodea1 » Wed Feb 19, 2020 12:32 am

today a new TB arrived, tested it and it appears to give nearly identical % and V at the same perimeters. here is the log. the only difference i noted is that the min voltage for TPS1 is showing 0.61V and TPS2 at 0.57V....not enough i would think to prevent things.

again logs are attached. I am hurting here to figure this out!

Is it prudent/ok to just mark the p2135 as 'no error reported' and forget about trying to figure this out?!

Any help would be greatly appreciated!
Attachments
new TB.zip
(839.02 KiB) Downloaded 107 times
~Ryan
Charleston, SC

Oldblue68chevy
Posts: 45
Joined: Mon Aug 21, 2017 12:06 am

Re: TPS1 and TPS2 disagree...P2135...need some help getting data for baseline

Post by Oldblue68chevy » Wed Feb 19, 2020 1:42 am

Im not an expert but I believe the pedal, tac , and tb have to all match. If you have all of the components from the caprice i would hook those up and see what result you get. Especially if they all worked prior to the swap. If you arent in a huge rush i could hook up to my car and see what readings i get probably this weekend.
2011 PPV 9C3

rcodea1
Posts: 21
Joined: Fri Jun 07, 2019 5:58 pm

Re: TPS1 and TPS2 disagree...P2135...need some help getting data for baseline

Post by rcodea1 » Wed Feb 19, 2020 7:17 pm

thanks for the assistance! I am looking for about 6 pieces of data

TPS1 %
TPS1 Volts
TPS2 %
TPS2 Volts
Acc Pedal Position 1
Acc Pedal Position 2

From that i think i can figure it out.

My worry is that the data i am seeing shows a huge difference between TPS1 % and TPS2 %....and i am not sure if this is an issue inside the ECM, or if this is normal for these cars. Im guessing its not normal, but i have no way to confirm that without getting my hands on another PPV locally.
~Ryan
Charleston, SC

rcodea1
Posts: 21
Joined: Fri Jun 07, 2019 5:58 pm

Re: TPS1 and TPS2 disagree...P2135...need some help getting data for baseline

Post by rcodea1 » Fri Mar 20, 2020 7:40 pm

UPDATE:
so last night i changed three things and did a 'write entire':
1)started from an original file and made a copy of the working 39...all the to eliminate the chance of a corrupt cal.
2) going off the idea that the MAF fail process i was doing may not be working, i refailed all the MAF settings, so the DTC p0102 is now current, not just permanent
3) upped the 'virtual torque' tables too by 30%.

I am not sure which of the three changes worked, but tonight i was able to drive around AND stab without causing REP.

I think the MAF fail is the most likely cause of my issues, which makes since. With it not being a current code, i think the ECU was continuing to look for a MAF signal, particularly when in transition.
~Ryan
Charleston, SC

Post Reply