reduced engine power

[mboard]

For the past 3 months I have a periodic problem of reduced engine power warning light coming on and of course at same time this reduces (governs) engine power to top rpm's of around 1500. This can be reset by turning ignition on/off many times. I have had serviced and some parts replaced with no success. Anyone else experienced this or similiar?

[mboard]

For the past 3 months I have a periodic problem of reduced engine power warning light coming on and of course at same time this reduces (governs) engine power to top rpm's of around 1500. This can be reset by turning ignition on/off many times. I have had serviced and some parts replaced with no success. Anyone else experienced this or similiar?

[Big Z]

Only experienced that on the boat. It went into "LIMP MODE" do to overheating. It has a vortec engine also. Just a thought, but have them check out the temp guages, thermostat, Etc.

[Hummer Man]

YEAH! it happened to me once & then never again!

[CO Hummer]

Happened to me when I left some lights on overnight and completely drained the battery. After I jumped started it and turned off-n-on several times I kept getting it. Then I left it off for 10 minutes and it worked fine.

[mboard]

Thanks for reply's. Just to make readers a little clearer on problem, this is happening at different driving conditions each time and occurs 2-3 times per week. This week engine shut off completely when warning light came on. It restarted immediately so I could get off road and then took 3 times to reset. Help wanted.

[Big Z]

Have your dealer replace the computer.

[MAC]

This never happened to my Hummer.
But the same thing happened to me on 2 brand new Mercedes Benz and on a Jaguar. Few times on the freeway at 65-75MPH, total shut down but managed to restart when still rolling, by itself or restarted engines, very scary.
On the Mercedes took several fixes to fix the problem.
Jaguar was caused by a smog chip recall which was never taken in as requested, took it to independent shop many times to fix the same shut down problem, wasted money but same problem, only the Jaguar dealer knew what it was and took care it no charge on one trip.

[mboard]

Thanks Mac. I have passed on your info to dealer. They have had my H2 for a couple days now, but have given me a new H2 until mine is fixed. Hummer is flying out an engineer to work on vehicle.

[prplprowlr]

Had this happen to my wifes 2001 Yukon XL 5 months after we bought it, they changed the computer and it kept doing it. They had my car for 3 months and placed 2500 miles on her car test driving it to see if they could fix it. The end result was GM replaced my wifes Yukon with a brand new Yukon XL with the same trim. We traded it (new car)and got her a Denali and have not had a problem with it so far. It seems to be a more common problem in the new GM's

[BADRAP]

Well I just tried to uninstall the Granatelli programmer from my Hummer and the display screen said REDUCED ENGINE POWER and then it would idle, so I had to reinstall it to make it run right.. It would not idle and when I stepped on the accelerator it would not rev up... So not sure what the deal is... Hopefully I will get this fixed...Any ideas?

[mboard]

Hi BADRAP,
As mentioned on this topic I have had numerous challenges with "reduced engine power". Hopefully this is a one or two time occurance for you. My H2 was in for a week recently and I must say Hummer Corp people (not dealer) were very accomadating. They called me every 3 days and finally sent a corporate engineer out to Reno to look at H2. They ended up looking at wiring harness from accelerator to engine and some of the connection points. All fo the crimped connectors were replaced and soldered on. I got it back on Thursday. When I picked it up they also attached a computer to the H2 that I must start up each time I start the vehicle. If there is a "reduced engine warning" I am to press a button which saves the last minute of operation and continues to record statistics. Kind of like "black box" on aircraft.Well on Saturday morning I received the "reduced engine power" again and pressed the button. I then called Chad Hall (races for Hummer race team, and is dealer) and he came and picked up H2. I will kepp everyone posted on what is found out next week in case you have same problem.

[mboard]

It has been a couple weeks since last (I hope final) fix. The dealer along with Hummer engineer ended up replacing entire wiring harness. At one end of the harness at top front of engine they found 15-20 splices in harness from factory. Splices were quick solder connectors that were not properly installed. They do not know why factory would have done, but???. So if anyone is having problem or looking at your wiring harness you may check this out as I have had my H2 since July 10, 2002 and problem started occuring just a couple months ago.

[steepndeep]

common problem,in most cases the throttle actuated control module fails.if so then the throttle body needs to be replaced

[CJ]

I had the same symptoms on my prior vehicle and it turned out to be a bad installation of a anti theft device. it was wired to the convenience circuit and caused an increased current draw. RPM stayed the same but power to the wheels was severly diminished.

[Hum2]

Throttle Body Assembly failure....I was washing the H2 the night I returned from 4 days of off-roading (in the middle of nowhere)...that was lucky!! The dealer said they had to have 2 instances of "reduced engine power" before GM would let them replace it. I would surely have been mad had it happened while 250 miles out! My first instance was last winter.

Ric