Alright folks! I've been trying to get this truck finished so that I can create a build thread and post some results, however I have some Drive by Wire problems that are standing in my way and would appreciate some help!


Set up: 2003 Sierra, drive by wire, x-link 4.0, 90mm LS2 Gold Blade throttle body, 3 bar Speed Density Tune.

We were out tuning on 10psi at WOT when the truck went into reduced engine power and threw a P2135 code. We were eventually able to get the truck started by quickly clearing the codes and it limped home in REP and no accelerator pedal input would change speed/rpm.

Currently, the truck will crank and fire, but then immediately die. After dying, the throttle blade will flutter for a few seconds then quit. The P2135 code will not clear and is present as soon as I power up the ECU. I have: 1) swapped in a different throttle body, 2) swapped in a different TAC Moduel, 3) swapped in a different pedal position sensor, 4) verified the x-link Ohms IAW the trouble shooting procedures, 5) verified 5V is being supplied at the throttle body tps sensor (gray wire), 6) verified the integrity of the stock wiring harness to the best of my abilities, and 7) verified TPS signal (%) and Throttle Pedal Position (%) is working via logging with HPTuners. This weekend I will remove the trans mount and lower the trans down so I can reach the grounds on the back of the block to make sure they're clean and tight.


Month prior to this issue, the truck developed an issue when after flashing a tune it would take several attempts to start the truck to keep it running. Additionally and more recently, I'd have a 'Charging System' message on the dash on first start up that would disappear in seconds without any codes being set. (just providing this information in case it jogs someone's memory - unsure if these issues are related to the current p2135 issue).


So....I am kind of unsure where to go from here. Any suggestions?

 

Have you tried it with the stock throttle body, tac module and APP?

I believe that all three need to match in some cases to prevent REP mode.

 

With the stock/original TAC and APP, I plugged in a stock TB and no change.

I have heard about all 3 needing to match, however haven't been able to confirm it...

 

Reflash the tune. Sounds like you many have flashed a corrupt file.

 

I went through this recently...tac module, app, and ecu should match. TB doesn't matter, atleast it didn't in my case. But I definitely had to swap all 3 to match lol.

 

Thanks settlemoore! Good to know. Can you elaborate more on the issue you were having? How did you get the TAC Module, APP, and ECU to match - pull the entire system (3 main components) out of another truck?

 

My issue was the 06 virtual flex fuel ecm not taking the 80e segment swap, so we swapped the ecu for an 04 and the segment swap took but it would go into rep, so the dude that put it together ended up swapping over all 3 pieces from another truck and then everything worked fine. Super strange lol.

 

Not really. The 03-05 operating system use a different Pedal, Tach module, Throttle body. The throttle body itself might be the same, however I have seen enough issues that I personally do not do it. I use all 3

06-07 classic are different Pedal and Tach module, the 2 components are not interchangeable with the earlier years.

The Computers are virtually Identical. I have an 2003 PCM in 2006 truck running a 2006 operating system. With 2006, Pedal, Tach and TB.

When doing a segment swap you need to do it with a 4L80E operating system of the same year. Sometimes there are differences in the background of the tune that can not be seen. Then you should full flash the new File.

 

Kyle - I gave it shot, but no change.

 

With KOEO (key on engine off) can you clear the code(s)? If they clear, cycle the throttle with KOEO. If they do not clear, unplug the harness as it goes into the X-Link. Plug in your original throttle body (or a known good one) and do the same test.

It looks like you tried that above, I just wanted to make sure.