P1516 engine code

[Sicksty8]

Now this isn't on a swap truck but I was hoping someone would still be able to help me out anyway. So my daily driver 03 silverado 1500 5.3 keeps throwing a P1516 code causing me to lose complete throttle input control. A message comes up in the cluster saying reduced engine power and when I scan it it says throttle actuator control. So I tried replacing it and the same thing still happens. Now I've heard it could be a block ground problem but I haven't checked that yet. Just wondering if anyone has ever had this problem and been able to fix it.

[BR3W CITY]

Usually caused by an error in (or a mismatch of), the TAC system. So thats the TAC, the TB, the ECM, and the pedal.

Since its not a swap, I'm ruling out a parts mismatch unless you had recently replaced something (before the error occurred).

Look at the purple and yellow wires coming off the TB. Lightly tug, wiggle them and look for cracking/breaking/fraying within ~4-6" of the TB. Also make sure they are not pulling out of the molex plug, or aren't physically pinched or broken.

There is also a grounding point (at least one) on the back of the engine, which can cause lots of fun problems.

Did you do anything to the truck (mods, tune, wheels, anything) before the error?

[Sicksty8]

Originally Posted by BR3W CITY

Usually caused by an error in (or a mismatch of), the TAC system. So thats the TAC, the TB, the ECM, and the pedal.

Since its not a swap, I'm ruling out a parts mismatch unless you had recently replaced something (before the error occurred).

Look at the purple and yellow wires coming off the TB. Lightly tug, wiggle them and look for cracking/breaking/fraying within ~4-6" of the TB. Also make sure they are not pulling out of the molex plug, or aren't physically pinched or broken.

There is also a grounding point (at least one) on the back of the engine, which can cause lots of fun problems.

Did you do anything to the truck (mods, tune, wheels, anything) before the error?

Thanks. No mods, no changes, just a few steering lines and oil changes. The problem happened and I swapped the TAC and the same thing happened. I'll take a look at the TB wires tomorrow. Would it happening as the weather getting colder make any difference? Because it happened in the spring and now in the 5*C fall weather. Never happened in the summer.

[Jason7121]

Have seen several of these where the connections at tac module have loose pins. Wiggle connections at tac. Also does it crank slow have seen several where low battery voltage causes p1516

[BR3W CITY]

Originally Posted by Sicksty8

Thanks. No mods, no changes, just a few steering lines and oil changes. The problem happened and I swapped the TAC and the same thing happened. I'll take a look at the TB wires tomorrow. Would it happening as the weather getting colder make any difference? Because it happened in the spring and now in the 5*C fall weather. Never happened in the summer.

Temp makes plastic rigid, so wire jackets get brittle. A partially broken wire will act up more in cold.

[Sicksty8]

Originally Posted by Jason7121

Have seen several of these where the connections at tac module have loose pins. Wiggle connections at tac. Also does it crank slow have seen several where low battery voltage causes p1516

As far as I know the battery works fine. Never had a starting problem.

Originally Posted by BR3W CITY

Temp makes plastic rigid, so wire jackets get brittle. A partially broken wire will act up more in cold.

Makes sense.