Throttle Actuator Control Module

[jaydentruman]

Hi I have a 2005 Chevy Avalanche 1500 with the 5.3L non-flex. I am having issues with my throttle body and specifically I believe the throttle control module. I was backing into a stall when randomly I received the reduced engine power display and I lost all throttle response and the idle became rough. I did all the things I thought to get it going, resetting sensors, wiggling the grounds, and ensuring all plugs are connected. And it still wouldn't run right. And I believe my issue is with TAC or throttle actuator control module as when I start my truck it will run fine with no issue but the second I hit the gas the message returns and the zero response and rough idle comes back.

I am going to the junkyard to grab a new one to ensure that is the issue as rockauto won't get to my house till later this week and the local shop wants $550 for the part alone. So I will get the part and see if it works and if it does Imma get the one from rockauto. However, I want to see if anyone else has any other ideas.

The codes coming up are the following: p1516 p2108 u0107

Thank you all!
Jayden

 

[99Sierra2500]

Check the fuse too. I think there might have been a service bulletin for a software problem.

 

[jaydentruman]

Do you know what fuse it is as I am struggling to find it

 

[99Sierra2500]

Didn't find it, though this is a good place to to start looking: https://charm.li/

 

[jaydentruman]

Fuse is good. I have cleaned a few grounds and replaced the TAC but still nothing. I am unsure if the issue and any help or ideas is appreciated

 

[jaydentruman]

The only thing with issues in the throttle and I am becoming very unsure of what is causing this. Everything is fine and the truck with start and run fine for a second or two and then the warning comes up and it begins to run rough but won’t stall. Just like it’s running rich or lean

 

[stutaeng]

I've never had this issue, but I know it can be a problem on some trucks.

I recommend you look up a wiring diagram and get some t-pins and backprobre the throttle body/TAC module and ECU and run a temporary set of wires with jumper leads. It doesn't have to look pretty

What you are trying to do is: create an alternate electric path for the signal. If you have an issue with your wiring harness (which I think is where the problem lies), the symptoms should go away after driving around. Then you know where the problem lies.

Worst case is you run a stand alone wiring harness to the throttle body...

I hope this helps.

 

[99Sierra2500]

The only thing with issues in the throttle and I am becoming very unsure of what is causing this. Everything is fine and the truck with start and run fine for a second or two and then the warning comes up and it begins to run rough but won’t stall. Just like it’s running rich or lean

Like @stutaeng said, maybe jumper a wire from the can bus, because it isn't communicating with the pcm.

 

[ORVietVet]

I am not at my laptop and hate looking up codes on my phone. What is related to the codes?

 

[99Sierra2500]

I am not at my laptop and hate looking up codes on my phone. What is related to the codes?

The U0107 is the TAC is not commmunicating with the PCM. P1516 is the throttle position out of range, P2108 the TAC has a problem with read/write or other fault.

 

[jaydentruman]

I am thinking it might be the acceralator pedal and sensor as I have inspected as much of the wiring as I can and everything looks perfect. I am hoping this will be the issue as It was such a sudden chnage which doesn't make me think it was wiring. Especially sense the fuse has never blown. So I am going to check that today as well and see if I can get it moved from where it is to somewhere I can look at it more.

A guy was talking to me and his buddy had the same issue as similar codes and it was the pedal as well. SO i am picking up a pedal assembly and I will plug that in and see if that is the issue.

The truck has 320,000kms and the pedal is definitely original and has a decent amount of surface rust on the pedal bracket so i am thinking mositure got in. Espically since I live in Alberta Canada and we have winter from nov-april with a LOT of snow and cold

 

[ORVietVet]

I am thinking it might be the acceralator pedal and sensor as I have inspected as much of the wiring as I can and everything looks perfect. I am hoping this will be the issue as It was such a sudden chnage which doesn't make me think it was wiring. Especially sense the fuse has never blown. So I am going to check that today as well and see if I can get it moved from where it is to somewhere I can look at it more.

A guy was talking to me and his buddy had the same issue as similar codes and it was the pedal as well. SO i am picking up a pedal assembly and I will plug that in and see if that is the issue.

The truck has 320,000kms and the pedal is definitely original and has a decent amount of surface rust on the pedal bracket so i am thinking mositure got in. Espically since I live in Alberta Canada and we have winter from nov-april with a LOT of snow and cold

The U0107 is the TAC is not commmunicating with the PCM. P1516 is the throttle position out of range, P2108 the TAC has a problem with read/write or other fault.

That is why I was asking about the codes. I had a similar problem with my 2005 Tahoe, couple years back, and it was the pedal assembly.

 

[jaydentruman]

Ok sweet. I hope its that. I am out of class in like 30 mins and im just going straight to install theb pedal. Ill keep yu updated

 

[jaydentruman]

So we still have problems. Even with the new pedal and new throttle control module. It’s still not working right. I re read the codes and I will post them here. Is this seeming like a wiring issue or a ECM or PCM?

 

[jaydentruman]

evap is a code I have been chasing for a little and is unrelated

 

[99Sierra2500]

Pedal has to do a relearn, iirc.

 

[jaydentruman]

how would i do that?

 

[99Sierra2500]

Use a scan tool and make sure the pedal reads within the range of idle to wide open throttle, someone else might be able to say more.

 

[Tonimus]

I believe 2 hours without the battery connected will reset both the throttle body position and the pedal position sensors. Overnight should definitely clear those parameters.

 

[jaydentruman]

I HAVE SOLVED THE ISSUE AND IT WAS A DOOZY.

After spending another 3 hours changing the throttle body, cleaning EVEN MORE ground, and taking apart and cleaning the pins of the connectors, I came to the conclusion it was none of them. I left teh truck running and went to wiggle the grounds and since it was dark while I was working I saw something arching. This is where the steering colum caught the plug wire and pulled it off which was causing the coil to arch to the cylinder head, which is where teh PCM is grounded too which was then sending bad throttle voltage and messing up the entire throttle system.

I never caught this issue as there WAS NEVER a code for a misfire which I am still confused about and I am happy to have it fixed. Im picking up a new plug wire as the old one was pretty chewed up and then I believe everything should be back to normal.

But man what the heck, out of all the things I thought it was i was shocked to find it this.


Thank you everyone for the help and messages!