Here's a weird one...

[Rocket Man]

It's actually called the Throttle Actuator Control module and it's under the hood on trucks with DBW throttles. And it should have thrown a code for sure.

 

[rockola1971]

It's actually called the Throttle Actuator Control module and it's under the hood on trucks with DBW throttles. And it should have thrown a code for sure.

All 3 of mine are DBW. Is that the module on the firewall in between the master cylinder and the drivers side fenderwell?

 

[DJ BigDog]

Update to update: Tech has module installed still limp mode solved but intermittent short to system still happening on bumps. That's what shorted out the Module and blew it in the first place. So now hes chasing a short and after calling GM TAC LINE he's officially on his own because they had no clue what to tell him.... OH BOY...

 

[Tonyrodz]

What was causing your limp mode, ie reduced power.

 

[Rocket Man]

All 3 of mine are DBW. Is that the module on the firewall in between the master cylinder and the drivers side fenderwell?

I'm not sure, I've never replaced one.

 

[rockola1971]

What was causing your limp mode, ie reduced power.

Anytime the Throttle position at the throttle body and the commanded position which comes from the potentiometer via the throttle (Gas Pedal) has an error within a certain percentage you will go into a limp mode. These two signals are fed back and forth via the TAC Module.
Heres a link how the system works for those that like to know how stuff works: http://easyautodiagnostics.com/gm/4.8L-5.3L-6.0L/electronic-throttle-body-2

Another common part failure that will cause this code is the TPS and its wiring harness at the throttle body. (Its pot gets worn out and dirty or electrically open spots within its 1-100% range). I just had this problem on my 05 Yukon Denali. Id get around 75% throttle position or so at the pedal and it would just slam into reduced engine power mode and literally reverts to idle speed and wont go any higher without shutting engine off and it clearing. This prevents engine runaway because of faulty DBW parts.

 

[Tonyrodz]

I miss the good old days of carbs and throttle cables.

 

[PG01]

Battery wires at the battery, starter and chassis ground connection. Check'em.

X2

 

[iamdub]

I miss the good old days of carbs and throttle cables.

Eeew- carbs. But I do like a good ol' throttle cable.

 

[Tonyrodz]

Eeew- carbs. But I do like a good ol' throttle cable.

Yeah, carbs are ancient, but was just trying to make a point. We've come so far with technology in cars, and the manufacturers are trying to get rid of the garage mechanics. Pretty soon, to fix or diagnose a problem, you're going to need a degree in rocket science or something.