2003 GMC Yukon Denali engine problems

Filed Mar 21, 2018 · Acceleration, Driver assistance · 152,000 miles · NV

I have a 2003 yukon denali I purchased and it has given me the reduced engine power light and almost had a few accidents on the highway because it drops the speed to 20 MPH also it has the check engine codes as p0120 and p2135 I have been aware that gm has not found a solution to this and wanted to see if there is any recalls as I am very afraid of being in a very serious accident with my children in the car. The consumer stated the vehicle was repaired and requested withdraw the complaint.

Filed Jul 23, 2014 · Engine, Transmission · 220,000 miles · AL

Tl* the contact owns a 2003 gmc yukon denali. The contact stated that the vehicle decelerated and stalled. The reduced engine power indicator illuminated. The vehicle was taken to the dealer six times to repair the throttle body, pedal switch, and wiring harness, but the failure recurred. The failure mileage was 220,000. Updated 10/02/14*lj updated 3/9/2015

Filed Mar 6, 2014 · Engine · IL

We have a 2003 yukon that will shuts down anywhere and anytime, the following example has happened more than once. We were driving on the highway when "reduced engine power" "stability traction loss" appeared on display - I pressed the accelerator and the vehicle would not move. I had to completely shut down the engine wait a few minutes then restart in order for the vehicle to operate correctly and a couple miles down the road, it happened again. It was a snowy mess out side which made the situation worse. This is a major safety concern as I am unable to accelerate in order to avoid an accident. I get scared because there could be a semi behind us and it will just plow into us because we can not do anything until we shut down the engine and restart. Very scary. We researched this issue to find other people are in the same situation and no one seems to know how to fix it. This is a long standing issue, gm is aware of this issue but will not issue a recall. Gm seems to be having alot of problems that they are not dealing with. Shame on gm!

Filed Feb 24, 2014 · Engine · 140,000 miles · NY

Engine leaking oil rear crank seal and plate. Gmc said seal will not be enough, need to replace plate. Defective. My mechanic charged me $710.41. Gmc should be reimbursing me.

Filed Feb 6, 2014 · Acceleration, Electrical · 125,000 miles · MO

Driving on hwy going aprx 65mph. Vehicle said reduced engine power and started slowing down. I had to pull to side of the road. I managed not to be rear ended. This has happened often. It is a potentially life threatening situation. Gmc know about this problem and how difficult it is to find the proper fix. Someone is going to die due to their lack of action. It's not safe.

Filed Dec 30, 2013 · Engine · 213,000 miles · NY

Tl* the contact owns a 2003 gmc yukon denali. The contact stated that the traction control and the reduced engine power warning lights illuminated and caused the vehicle stalled. The contact was able to restart the engine, which resumed normally. The failure was recurring. The vehicle was taken to the dealer, who was unable to diagnose the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure and current mileage was 213,000.

Filed Nov 11, 2013 · Acceleration, Driver assistance · 83,000 miles · IL

The service engine light and traction control turn on and the information center on my cluster reads "engine power reduced" and "stability system disable", then my speed is reduced and only runs between ten and twenty miles per hour. I have to turn off my truck and turn it back on after a few minutes to continue, but this problem has happened on a daily basis. I think gmc is responsible for this and more similar problems.

Filed Oct 19, 2013 · Acceleration, Engine · 128,000 miles · VA

I was driving approximately 65 MPH uphill when my engine and traction light came on. My speed was immediately reduced to about 35 MPH even though I tried to accelerate. I drove home about 8 miles at a reduced speed because I had my children in the truck and it was raining. I took the truck to a mechanic the next day and he replaced the throttle body. I picked up the truck that evening and as I was driving home the same thing happened again. I took the truck back to the mechanic, the check engine light and tc light was on again however he said that there was nothing wrong. His thought was to replace the throttle body again. Two replacements later, the problem remains.

Filed Dec 16, 2011 · Driver assistance, Electrical · 97,000 miles · GA

I have had multiple ongoing electrical issues with this vehicle. Starting in 2005, the exterior electronics (I.e. Signal lights, stop lights, head lights, etc) began to malfunction. For example, I would trigger the signal for one direction and all of the signals for all directions would trigger... Even pressing the brakes triggered all of the exterior signals. The dealer had a hard time isolating my problem, but after several visits, the dealer was finally able to diagnose and rectify it... They isolated it to a junction box where all of the electronics terminate. However, by this time, my vehicle was out of warranty, so I had to cover the costs for repairing the problem myself. My most recent issues, which, by the way, seem to be common issues, are triggered by a message stating, "reduced engine power". This particular issue does not always render the same results... Sometimes the vehicle's speed will significantly decrease to nearly a halt, but other times I may just experience increased idling of the engine, even if I am at a complete stop. My understanding, according to hundreds of reports that I have read on the message boards, is that this issue is caused by either a wiring harness that leads from the accelerator to the throttle body or it's a defective throttle body altogether. I have experienced intermittent electrical problems with my windows as well, but this appears to be a minor issue when compared to the other two that I addressed above. I will file a formal complaint with gmc corporate office today and see where that goes.

Filed Nov 22, 2011 · Driver assistance, Electrical · 117,000 miles · OK

December 2008- instrument cluster went out- speedometer no longer working december 2008- battery gauge no longer working march 2009- stabilitrak issues...sometimes the stabilitrak would work and at times it would not work july 2009 to january 2010- reduced engine power (almost cause 2 wrecks) could not perform a diagnosis...could not read computer. Changed fuel pump. No more reduced engine power message august 2011- wheel bearing issues. Reduced engine power (almost caused wreck...backed up traffic) september 2011- gas pedal sticking november 2011- reduced engine power...happens 5 times within a 30 mile trip. Attempted to resolve problem several times, but running out of options. Have to kill car in middle of highway or intersection to get car to work properly.