2003 Silverado 2500HD REDUCED ENGINE ...

Canton, OH

#42 Nov 13, 2012
Bought a 2003 Chevy HD...have had nothing but trouble. All the breaklines blew...only had 94K miles. I have no power when hauling anything. I hook my trailers up to a Ford Diesel and you can't even tell your hauling anything. Huge difference...first and absolute last time I will buy a Chevy. I have also had a problem with my gauges going out...my spedometer will accelerate on its own. While driving in town, I look down and it said I was going 90mph! Highly unlikely. I have been told that the instrument cluster goes out on this make as well? Has anyone else had this problem? Any advice? Have those that replaced the THROTTLE BODY AND MODULES had any luck once they've been fixed?

Nobleboro, ME

#43 Nov 14, 2012
2003 chevy 2500 hd same trouble spent more on repairs then i paid for the truck in dec 2002 at dealer, still does it up to ten times a day
Db rider az

Peoria, AZ

#44 Nov 24, 2012
yeah theese trucks are crap, replaced tac module, throttle body wiring harness, still gets the reduced engine power. Any way to scrap the drive by wire system? IT SUCKS!

Easley, SC

#45 Jan 3, 2013
Do you still have the 2003 Silverado? I am having reduced engine light problems.
mike wrote:
I also have a 2003 2500HD. I get the reduced engine power all the time. I clean the sensor even replaced the mass air flow sensor and it still does it. Seem everyone that has this truck has a problem I am thing a mass law suit with GM to make them do a recall on this. If everyone sends in to the attorney general. We can force GM to fix this mess.
I already sent my complaint into the Attorney General.


#46 Jan 3, 2013
Catalytic converter plugged.

Easley, SC

#47 Jan 4, 2013
I will have the catalytic converter checked.

United States

#48 Jan 19, 2013
i had the same problem i bought a hoe gas pedal from gm and the wire that goes to the box on fire wall and fixed it

United States

#49 Jan 19, 2013

Cleveland, OH

#50 Jan 22, 2013
i get the reduced engine power with code p1516, guy at autozone said it was the throttle body, replaced it and added a cold air intake, that just made the problem worse. my battery tested bad so i replaced it, that didnt work. cleaning MAF today, if that doesnt work im checking wiring and grounds this weekend. and like evryone else my truck is SUCKING fuel!
2003 2500HD 6.0 gasser
big a

Humble, TX

#51 Jan 22, 2013
i had that same problem to . with my engine reduced power. if your coolant antifreeze has broke down in other words your antifreeze is old. and you run your vehicle long period of time. like usin your ac or heat . your engine reduced power indicator will come on and your check engine lite will come on to.change your antifreeze and flush your system out.that will take care of your problem gauranteed

United States

#52 Jan 23, 2013
big a wrote:
i had that same problem to . with my engine reduced power. if your coolant antifreeze has broke down in other words your antifreeze is old. and you run your vehicle long period of time. like usin your ac or heat . your engine reduced power indicator will come on and your check engine lite will come on to.change your antifreeze and flush your system out.that will take care of your problem gauranteed
My truck just got put in the shop this morning, I don't think that's the problem because it mainly happens on slow acceleration. If I put it to the floor it won't come on, but I'll mention that to my mechanic. I would do it all myself but I didn't have time between two jobs and a new baby haha.
2003 suburban 2500

Tucker, GA

#53 Feb 1, 2013
I have a 03 suburban 2500 6.0 and driving down the road this morning on a smooth road I lost power. It said reduce power it would idle but no throttle.. Took to shop and he said that my battery was dead but when I got it towed it was fine I checked it with meter.. What should I do I don't want to replace one thing after another to not get the problem fixed it almost got me killed. What should I do.. Thanks

Plattsburg, MO

#54 Feb 1, 2013

I think you are one Jap paid shill posting under various proxies spreading Toyota piece-of-shit propaganda.

GM makes the finest autos on the planet for the money. Toyota doesnt even have one to compete with the 2500 truck, or the Camaro or the Cadillac, or many other fine GM products.

Same goes for Ford or Chrysler.

Whatever, I have my GM that I have driven for 10 years and look to drive for another 10 years. I'm not in the market for any new autos.

Easley, SC

#55 Feb 1, 2013
Had throttle body replaced. So far, so good.

Pflugerville, TX

#56 Feb 10, 2013
yesterday it went into 'reduced engine power' mode 4 or 5 times when i left the house. it was 50 degrees and rainy. last week it went into mode once or twice in the morning then i would spend the day driving to and from jobsites with no issues. happens in the first 30 minutes in the morning, more frequent when cold. went to dealer, spent 45 minutes talking to techs, since the check engine had cleared itself they said nothing could be done, except change out the ecm(computer). went to auto zone, read codes P1516 and P0174. i have cleaned air intake previously and it reduced the frequency of occurence, after reading codes i replaced the MAF sensor. still same issues. replaced fuel filter a few weeks ago, no help. there is a you tube video showing a connection issue, guess i'll try that next. 2003 suburban, 250k miles.

by the way, went to trade the vehicle in for a 24k advertised truck, after the salesman finished his spiel it went to 29000. seriously....

Steubenville, OH

#57 Feb 10, 2013
I replaced my throttle body with a cardone brand from AutoZone, needless to they are junk. That throttle body was also bad. I replaced my throttle body with a GM one, New pigtail, and cleaned and tighten the ground s. Good for 2 weeks now! do not buy cardone brand parts!

Concord, NC

#58 Feb 13, 2013
I too have had the same issue with my 2003 2500 HD, I have spent the money replacing the throttle body, the TAC sensor and the wiring harness for the throttle body and I still have the problem, I think Chrevrolet needs to address this issue with all the post I am seeing from people with the same problem.

Pittsburgh, PA

#59 Feb 13, 2013
I actually called GM and they said not enough people actually call them to complain. If everyone who complained online would actually call GM the would probably do something about it. That's what they told me on the phone

New York, NY

#60 Mar 2, 2013
I also have a 2003 GNC 2500HD 6.0 Same thing reduced engine power so far replaced throttle body,replaced TPS,replaced TAC on fire wall,replaced ECM,checked all grounds under hood? Now it will do it when its cold once or twice then will run fine till the next day.Dont know what to do next but going to check some more grounds also 5volt that goes to throttle body ?

Coraopolis, PA

#61 Mar 2, 2013
Check the pig tail the plugs into the TPS sometimes the wires in there crack and only make the connection sometimes. Lightly tug on each wire, if they move or you can see it slide in and out, theres your problem. Had mine replaced along with my throttle body works fine now. DO NOT USE A CARDONE BRAND THROTTLE BODY FROM AUTOZONE. it actually made my problem worse go to a dealer and get a GM replacement.

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