[Klutch Mclovin]

I have a 2003 Chevy Silverado 2wd with the 4.8L v8 and 156k. I was on the interstate going around 80mph and all of a sudden my truck just didn't accelerate when I pressed the gas pedal, I looked down and it said Reduce Engine Power. It slowed me down to 55mph until I got to the next exit and stopped at a gas station. I called my friend and he said the computer was sending out like an error code or something. He said to turn the truck off and start it up a minute later. It worked fine until I was almost home and did it again. I turned the truck off and on again. It pulled up again so my friend said to reset the computer and It happened again. Does anyone know why this is happening. I was going to stop by autozone tomorrow to get the codes and start from there.

 

[tbplus10]

Like you've already planned stop at AutoZone and get the codes sooner rather than later.
It's happening because your computer has detected a problem that could be fatal to the engine and it's putting it in "Limp" mode to save the truck from damage.

 

[Klutch Mclovin]

I was searching on google to solve this problem and this guy wrote this "Apparently there are two throttle position sensors near your gas pedal, A, and B. Actually they must be in the same module, but they apparently have independent electronics. Well apparently the output from A didn't agree with the output from B, so the code was set and the "reduced engine power" message was displayed, and your computer entered "limp" mode. Seems like overkill, to enter limp mode just because of the throttle position sensors being faulty... maybe they're keeping a fail safe on this because it's so highly critical that the throttle position sensor never malfunction in the sense that it applies more throttle than you were asking for. So if it's in doubt, limp mode ensures you could overcome the measly "reduced power mode" throttle with a light application of the brake."

 

[silveradotrailblazer]

X2 what Tim said. If you ran it hot it will go into reduced power mode/limp home mode along with other things that can trip the reduced power.

 

[Klutch Mclovin]

I am pretty sure it has to do something with the throttle body, but I won't be positive until I get the codes tomorrow.

---------- Post added at 06:16 PM ---------- Previous post was at 06:12 PM ----------

X2 what Tim said. If you ran it hot it will go into reduced power mode/limp home mode along with other things that can trip the reduced power.

I didn't run it hot, I was less than 10 miles from my house and I didn't drive my truck all day today because I was sick.

 

[99'HEARTBEAT]

I have a 2003 Chevy Silverado 2wd with the 4.8L v8 and 156k. I was on the interstate going around 80mph and all of a sudden my truck just didn't accelerate when I pressed the gas pedal, I looked down and it said Reduce Engine Power. It slowed me down to 55mph until I got to the next exit and stopped at a gas station. I called my friend and he said the computer was sending out like an error code or something. He said to turn the truck off and start it up a minute later. It worked fine until I was almost home and did it again. I turned the truck off and on again. It pulled up again so my friend said to reset the computer and It happened again. Does anyone know why this is happening. I was going to stop by autozone tomorrow to get the codes and start from there.

x3......on what Del and Tim have mentioned above and The Following Information is from the.....2004" Silverado Owners Manual its Regarding....(Reduce Engine Power).........

Section 3......Page 69,
REDUCED ENGINE POWER.......This Message is displayed when the Cooling System Temperature gets too HOT and the Engine further enters the Engine Coolant Protection Mode.......See Engine Overheating on Page 5-35 for further information.

Section 5.....Page 35,
Overheated Engine Protection Operating Mode (V8 Engines Only)
If an Overheated Engine Condition exists and the......REDUCED ENGINE POWER......message is displayed, an overheat protection mode which alternates firing repair. groups of cylinders helps prevent engine damage. In this mode, you will notice a loss in power and engine performance. This operating mode allows your vehicle to be driven to a safe place in an emergency. Driving extended miles (km) and/or towing a trailer in the overheat protection mode should be avoided.

 

[Klutch Mclovin]

Got this from the Gm service manual

Subject:SES Light and Reduced Engine Power DTC P0120 P0220 P1516 P2135

2003-2006 Chevrolet Avalanche, Corvette, Express, Monte Carlo, Silverado, SSR, Suburban, Tahoe, Trailblazer
Equipped with a 4.8 5.3 6.0 V-8 Engine

A vehicle may be brought into the dealer for a reduced power message, and DTCs P0120, P0220, P1516, P2101, or P2135.

The Throttle Actuator Control (TAC) / throttle body type trouble codes, may be caused by a loose wiring crimp at the throttle body connector, or a broken throttle body circuit.

1. Inspect all related throttle body terminals for a loose wiring crimp. The loose crimp may be difficult to find, and the poor connection will be between the terminal and the copper strands of the wire. Wiggle test the individual throttle body circuits to see if the concern can be duplicated.
   
2. Inspect the related circuits for broken wires inside the insulation. The outer wire insulation may look fine, but the internal copper strands may be partially broken. Breaks in the wires usually occur within 1 to 4 inches of the throttle body connector. Wiggle testing may also induce a trouble code to set.
3. On C/K trucks complete SI procedures for voltage drop on grounds G103 and G104. Grounds G103 or G104 may be loose or corroded.
   

I will be more sure what it is tomorrow though.

 

[Klutch Mclovin]

I am positive I didn't run it hot. I went to three different auto parts stores today to get my computer checked and they all said there wasn't any errors. One of them said to take the positive off the battery for 25 mins and should that completely reset the computer so it won't happen again. It didn't happen today so I think its fine.