Code U0107 and related issue, maybe?
Thread Starter
On The Tree
Joined: Jan 2006
Posts: 180
Likes: 16
Code U0107 and related issue, maybe? The car is a '70 Impala; 2005 6.0 litre LQ9, all stock but Magnacharger blower; DBW; everything comes from a 2005 Silverado SS, except the 4L80E trans, but the computer was re-programmed for it, and it works great.
The car drives very little, maybe 300 miles a year. For the last couple of years, if I floor it, the engine will not rev above 4000/4500 rpm, it feels like it hits a rev limiter. If I do not floor it, it just accelerate, all is good. Before that, I could floor it and burn rubber, no issue, which tells me that all the components work well together. Otherwise, the car runs great, smooth, fast... as it should.
So today, I floored it a couple of times, just to see if it still "stops" at 4000/4500, and then, at a slow left-turn intersection, I lost throttle, CEL came on. I pulled over to the side of road, engine idled fine. I looked under the hood, fiddled with all the connectors related to DBW, on TB, on tac module, no gain. Then, I turned off the engine and started it right back: CEL still on, but I got throttle again, so I drove back home. Diagnostic code was U0107, "lost communication with Tac module".
I have looked online and here, no one seems to have exactly the same symptoms, as many people mention "limp home mode" with this code, which does not happen to me. Several people talk about bad grounds on the PCM and Tac... I have pulled on, and played with all the wires, all seems good, I had changed the pigtail on the TB a couple of years ago. Several people also say this issue appears after flooring the throttle...
So, is this 4000/4500 rpm limit connected to my new U0107 code? Is this just a ground issue, or?.. Where else can I look?
Thanks!
The car drives very little, maybe 300 miles a year. For the last couple of years, if I floor it, the engine will not rev above 4000/4500 rpm, it feels like it hits a rev limiter. If I do not floor it, it just accelerate, all is good. Before that, I could floor it and burn rubber, no issue, which tells me that all the components work well together. Otherwise, the car runs great, smooth, fast... as it should.
So today, I floored it a couple of times, just to see if it still "stops" at 4000/4500, and then, at a slow left-turn intersection, I lost throttle, CEL came on. I pulled over to the side of road, engine idled fine. I looked under the hood, fiddled with all the connectors related to DBW, on TB, on tac module, no gain. Then, I turned off the engine and started it right back: CEL still on, but I got throttle again, so I drove back home. Diagnostic code was U0107, "lost communication with Tac module".
I have looked online and here, no one seems to have exactly the same symptoms, as many people mention "limp home mode" with this code, which does not happen to me. Several people talk about bad grounds on the PCM and Tac... I have pulled on, and played with all the wires, all seems good, I had changed the pigtail on the TB a couple of years ago. Several people also say this issue appears after flooring the throttle...
So, is this 4000/4500 rpm limit connected to my new U0107 code? Is this just a ground issue, or?.. Where else can I look?
Thanks!
Spent about 3 weeks fighting a U0107 code in a buddy's '04 Tahoe, turned out to be an issue with the ground for the TAC module (not the actual TB or PCM, but the TAC module mounted on the firewall). I'd check the ground for the TAC module, as well as the wiring between TAC and PCM.
Thread Starter
On The Tree
Joined: Jan 2006
Posts: 180
Likes: 16
Spent about 3 weeks fighting a U0107 code in a buddy's '04 Tahoe, turned out to be an issue with the ground for the TAC module (not the actual TB or PCM, but the TAC module mounted on the firewall). I'd check the ground for the TAC module, as well as the wiring between TAC and PCM.
Although, thinking about it, I was very careful about all the engine grounds when I did my swap, but since it is a kind of "ratty" car (unrestored, original rust everywhere...), it does make sense! I was waiting for comments here before investigating the car, so I am going to try that, there is a nice, easy to access, ground point on the alternator bracket ( the battery is in the trunk).
Thanks, it does seem funny (ridiculous?) that it could be just a ground issue.
Although, thinking about it, I was very careful about all the engine grounds when I did my swap, but since it is a kind of "ratty" car (unrestored, original rust everywhere...), it does make sense! I was waiting for comments here before investigating the car, so I am going to try that, there is a nice, easy to access, ground point on the alternator bracket ( the battery is in the trunk).
Although, thinking about it, I was very careful about all the engine grounds when I did my swap, but since it is a kind of "ratty" car (unrestored, original rust everywhere...), it does make sense! I was waiting for comments here before investigating the car, so I am going to try that, there is a nice, easy to access, ground point on the alternator bracket ( the battery is in the trunk).
