Reduced engine power

KSIMS

MEMBER
2005 CHEVROLET SILVERADO
5.3L
V8
4WD
AUTOMATIC
165,000 MILES

Periodically, the engine light comes on and 'reduced engine power' is displayed on the dash.
I can shut it off and restart and engine performs normally. I can clear the U0107 - Lost communication with TAC module error but, the situation will return intermittently. Each successive restart will allow it to reset and run normally.
I'm wondering if replacing the TAC module would correct the issue or if it would require further investigation.

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

One of the most common reasons for reduced power/limp mode is a dirty throttle actuator.
Over time dirt and debris can built inside the throttle actuator and that can send faulty reading to the ECM, which can trigger the reduced power mode.

https://www.2carpros.com/articles/reduced-power-limp-mode

Typically cleaning out the throttle body and the components can fix the issue.

Here is a helpful guide on cleaning the throttle actuator:

https://www.2carpros.com/articles/throttle-actuator-service

I have attached the throttle body removal/installation and cleaning procedure below.

Please let me know if you have any questions.
Thank you.