'07 Tahoe Limp Mode!

[a2t]

why dont you lemon law it?

i saw an 08 hybrid at a dealer south of atlanta which had all sorts of similar issues. they lemon law'd it, then GM replaced the entire trans and they are now trying to sell it again (hennesy gmc).

i didnt touch it, bought another tahoe (which is having its own set of problems).

 

[bigblue]

could be something with the transmission, i have heard on these nnbs tahoes/yukons they have a sensor in the transmission that puts them in limp mode, when the transmission is about to tear up or if it gets hot.

 

[TahoeLTZ]

Hey guys, thanks for the ideas. What makes these forums great is all of us coming together to try and figure out these problems so others can possibly get something out of it in the future.

The Tahoe is at the dealership again. This time, they pulled up 9 stored codes that occurred in the last 3 days. 5 of them were from me pulling the ABS fuses in an attempt to disable the Stabilitrak and Traction Control, as well as ABS, to try and determine if they were malfunctioning and causing the limp mode. 20 minutes into my test drive, it happened again, even with these systems disabled. So I determined these systems were not causing my problem (but still dont like all that crap on my vehicle )

So, the tech ignored those 5 related to the ABS due to me taking out the fuses and causing the thrown codes. The other 4 were all related to the TPS, or throttle position sensor. This was good news as all the other code reads in the past only showed a generic "unable to communicate." After telling the tech that the engine actually DIED on one of the occurences, he stated that having a bad TPS would and could do that. He was almost as excited as I was to finally have a starting point. Unfortunately, he stated the sensor located on the throttle body is part of the TB itself, and would have to replace the entire throttle body... Hey, as long as it gets my Tahoe back to normal I dont care! I will know tomorrow if it is the fix....

 

[JEJ]

Hey guys, thanks for the ideas. What makes these forums great is all of us coming together to try and figure out these problems so others can possibly get something out of it in the future.

The Tahoe is at the dealership again. This time, they pulled up 9 stored codes that occurred in the last 3 days. 5 of them were from me pulling the ABS fuses in an attempt to disable the Stabilitrak and Traction Control, as well as ABS, to try and determine if they were malfunctioning and causing the limp mode. 20 minutes into my test drive, it happened again, even with these systems disabled. So I determined these systems were not causing my problem (but still dont like all that crap on my vehicle )

So, the tech ignored those 5 related to the ABS due to me taking out the fuses and causing the thrown codes. The other 4 were all related to the TPS, or throttle position sensor. This was good news as all the other code reads in the past only showed a generic "unable to communicate." After telling the tech that the engine actually DIED on one of the occurences, he stated that having a bad TPS would and could do that. He was almost as excited as I was to finally have a starting point. Unfortunately, he stated the sensor located on the throttle body is part of the TB itself, and would have to replace the entire throttle body... Hey, as long as it gets my Tahoe back to normal I dont care! I will know tomorrow if it is the fix....

And the answer was? Yaw sensor?

 

[TahoeLTZ]

Well, they replaced the TPS and it did it again right away. Knowing it was a dangerous issue (due to limp mode and at one point the engine quitting on the interstate) they kept it for a week at the dealership. I got it back with an additional 500 miles on the odometer, and they stated they did not find anything in particular but that is seems to be fixed. They stated they contacted GM and followed their instructions to a T by going through every wiring harness and connection, as well as every ground, and making sure they were tight. Dealer said they did not discover any that "appeared" loose, but that after they spent 3 days checking wires, they could not reproduce the problem. We have had it for 2 weeks now, and another 800 miles later it still has not done it. So my conclusion would be that it is wiring related, and probably a loose connection or ground that was giggled or tightened enough to fix it....................for now. Let's keep our fingers crossed! Problem is, if it happens again, who knows WHICH ground or connection was the culprit?

 

[TahoeLTZ]

Jiggled, not "giggled." Tho I am starting to just giggle at the whole situation.

SteveK is probably right: there was a short or loose wire connection. Whatever you do, DONT buy another alternator if you are having this problem. Oreilly Auto Parts tested the old one, and said it passed upon startup and then eventually "failed" after running for a few minutes, and suggested a new alternator. I now know THIS IS NORMAL with the new Tahoes, as the computer manages the alternator output based on electrical needs in an attempt to increase fuel conservation. The old one I had was most likely perfectly OK and I wasted 230 bucks. Just FYI.

My suggestion to anyone else experiencing this is to first check all the wiring connections and grounds on the vehicle. Say goodbye to a weekend.

 

[TahoeLTZ]

Well, after 1200 miles trouble-free miles doing everything from short little town trips to towing a 2 ton boat 300 miles, plus driving up in the hills to a remote cabin, it had to come to an end. Took the Tahoe to the brake shop to have the brakes inspected for a long trip coming up. They removed the wheels/tires and the inspection came back clean, so they re-mounted the wheels/tires without touching a thing. Then shortly afterwards, BAM!, limp mode on a 75 mph speed limit interstate. Not once, but twice within 10 minutes.

 

[viper911ad]

Hello,

I have a 07 Tahoe 5.3 LT. Having the same exact problem. It's happened twice now. First time I replaced the battery, but it's happening again.

Do you have any updates? How is it running now? What did you do to fix it this time?

Thanks,

Adam

 

[TahoeLTZ]

Why oh why am I bothering with this thing?!!??!!

Since I posted last my '07 Tahoe with 102000 miles has limp moded at least a dozen times. Once while pulling a 4000 pound boat up a hill -- that time it not only went into reduced engine power, it actually died while climbing the hill. Thank God for emergency brakes.

I have replaced the battery and alternator. Checked the gas cap for tightness. Checked the throttle body wiring harness connection for tightness and even zip tied the wires tight and then to a solid part on the manifold so I would KNOW the wires were not moving during engine operation (in case there was the common "split" inside the insulation). Still does it whenever the hell it wants. Sometimes 4 times a day, sometimes once every thousand miles. But usually when there are friends/family on board so I can be real nice and embarrassed that I drive a $30,000 POS. Problem is, I like it otherwise. I runs and drives better than any vehicle I have ever owned when not in limp mode. Chevy dealer had it for a total of 20 days over the course of 6 visits and they could not figure it out. Bittersweet I tell ya.

 

[IrishTR]

Probably not an viable solution but I would take it and get rid of it asap... Too much safety and headache concerns! If I ever have a car at a dealership (thankfully mine are all warrantied to 125k) and they tell me they cant fix it... Kiss it goodbye!