As a whole lot of others, my Suburban constantly goes into low power mode. If I shut it off, not recommended on a highway, and leave it off for a few seconds it goes away and starts normally. This returns a month or less and is always in the p1516 code. GM needs to do something as their dealers don't know what causes this and how to correct is another unknown!! This is a 6.0 litre motor with a 4wd automatic transmission and a heavy duty factory towing package. I have not heard of the 2014/2015 with this problem, but I will sure look it up !!! My1999 Tahoe runs better than this with no major breakdowns at all, and I bought it brand new.

I've already replaced the battery and the alternator, in the past two months and now something is draining them both again. There is constant loss of power and reduced engine power message. The lights constantly dim and it's not good when you're doing 70 on the highway (legal speed limit in my state) and all of a sudden your vehicle goes from 70 to 15. Other drivers get high road rage and there's nothing you can do about it. It seems a lot of people are having the same issue with this and even your dealers can not figure out what your issue is.

Took my suburban into dealer , they had it for a week. Cost $150.00 for nothing . they couldn't get it to do what i was talking about. On my 2 mile drive home i hit a bump and car died for a split second and reduced power warning light came up and performance is so bad i have to pull over shut car down and remove battery cable to reset system . After fiddling with positive cable for a while i was able to turn it over . This morning, July 18th, ignition clicked and reduced engine power sign came up. Had to fiddle with + battery cable again. This is getting worse. Anybody out there have any suggestions? Frustrated Fred

Our '03 Chevy Suburban has had the throttle sensor replaced 7 times, the foot sensor from the pedal replaced 1 time and all the wiring to the throttle sensor checked repeatedly. However, the engine light continues to come on and then the engine goes into reduced engine power. We are able to pull off the road, turn off the vehicle for several seconds and then it resets for a very short time only to continue the pattern. We've had 2 different mechanics work on this issue but they have told us they are stumped. We have noticed other complaints online with this same exact issue with this make and model vehicle. We would love to have a solution and at this point we are wondering if this is a manufacturing defect that has yet to be addressed by the manufacturer. Any help would be greatly appreciated!!

ARRG !, this couldn’t have happened at a more inconvenient time, right in the middle of traffic. I barely was able to get it back home, called a Wrecker and had it taken to a Chevy Dealer. They said it was a Wiring Harness Short, and are replacing that Harness. I haven’t gotten it back yet, and will attempt to edit/continue this comment, to name part exactly and it’s number. And, report if this really fixed the problem.

Update from Nov 6, 2011: This is a followup of a previous complaint for "Reduced Engine Power" message. I took it to the Dealer, and paid $670.00 to have it fixed. That didn't happen, and yesterday when I cranked it up, same message on display.

Going back to Dealer today, and telling them the same thing...

"FIX THIS THING WHERE THIS DOESN'T HAPPEN AGAIN" !!!!!

I took this vehicle to the Richard Kay Superstore to have a diagnostic done to find what the exact problem was. The mechanic told me that the engine was good, but the transmission was bad. He suggested a new transmission, $3,650.58. I asked the mechanic if he was sure that the engine was good. He confirmed that he had performed the diagnostic; the engine was fine. I paid the $3650.58 to Richard Kay Superstore, in Anderson, SC, located 1935 Pearman Dairy Road. When I retrieved my truck, the speedometer, and the dash lights were not working, that had not been a problem prior to the transmission repairs. I asked the mechanic why. The Richard Kay Superstore Mechanic dba/1935 Pearman Dairy Road, Anderson, SC, stated, "That's not our problem, we only fixed the transmission." The vehicle was idling, I asked why was that. Same response, "That ain't our problem maa'm we only fixed the transmission." The truck was not pulling, again, about two months after the repairs. I went back to the Richard Kay Superstore, 1935 Pearman Dairy Road, Anderson, SC. Same response. "That ain't our problem maa'm, we only fixed the transmission." Sounding like a broken record. The Chevrolet customer complaint service was just as sorry. We are sorry maa'm, but we have no recalls for your vehicle, and we cannot assist you with repairs." Dagum shame. I wont purchase another Chevrolet, and will do all I can to deter others from it. Until Chevrolet does right by me everything they set out to do will fail, their sales is going to drop 70% this year, and they wont be able to give a Chevrolet away until they do what is right concerning the poor service that they have done with me. Until they do right by me.

The truck runs great EXCEPT you never know when this problem will occur. I can be on a busy freeway and all the sudden lose power and not be able to go more than 15-20 mph. Very scary! The mechanic cannot seem to pinpoint the cause. Supposedly, he has checked all the wiring. It is very sporadic. I can go through a whole tank of gas with no problems and then there it goes....

Sometimes when I go over a RR track or bump, my ABS light and brake light comes on and my doors unlock, but I do not lose power.