'07 Tahoe Limp Mode!

[TREYR8D]

I dont think i saw anything about this in your postings, but i remember reading about it when changing wheels. I was reading in a corvette forum that if the TPMS sensors are unable to communicate with the vehicle, the stabilitrack system will put the vehicle into a "limp mode." You mentioned it was all fixed, then after having brakes checked it did it again where the wheels were removed.

I'd imagine the TPMS sensors have a finite life. Your dealership should have the testing tool to tell if they're all capable of communicating still. I had 4 all new ones reprogrammed in 2 minutes flat with this tool.

I dunno if this will help, but maybe something that hasn't been looked at yet. and the unable to communicate error seems more probable with sensors that are wireless, such as the TPMS.

Best of luck!

 

[TahoeLTZ]

Yeah Irish I tend to agree.........if the Chevy people cant fix their own product then there is something seriously awry...

Thnx Trey, at this point I am willing to try anything. Just spent 2 hours under the hood of it tonight, unwrapping ALL of the wiring from the TPS on the throttle body back as far as I could reach to check wires. All appeared fine and I could see the new splicing to the harness that the dealer recently did in one of their attempts to fix. Even pulled ABS sensor plug while engine running to see if that would do it. "Service Stabilitrak" did come on, but it did NOT go into limp mode. So those arent it either.

If it were the TPMS sensors, wouldnt I at least be getting the tire symbol and message to check tire pressure? Oh well, its worth a shot.

 

[doramide7]

There is a short somewhere, that's my only guess.

The voltmeter on the dash is not acurate at all. I have a 300 amp alt and the voltmeter will often hover around 12v, but my volt monitor I installed has me constantly at 15v(except when I'm playing my system at full blast).

I would suggest getting a multimeter and measuring the voltage (at the alternator and at the battery) after you have been driving around and the batt has had time to charge up. With your truck at idle, the voltage at your alt should be around 14.4v and close to that at the battery. If the voltage checks out, then its more than likely just an in-accurate meter on the dash, If the volts are low, then have someone get in the truck and rev the engine to around 2k-2500 rpm and repeat the measurement. If you don't hit 14v with the engine rev'd, then yea, you have an issue!

Like I said before, it probably is just your meter on your dash.

 

[TahoeLTZ]

Update:

We are having a No More Limp Mode Celebration!!! Been over a 1000 miles now and the Tahoe is running like new. The fix? The dealer finally re-wired the entire line from the computer to the throttle body. Not just the last 12 inches, but the ENTIRE line. Now, it could have been a break in the wiring, or the connection at the TB, or the connection at the computer----we will never know for sure. But one thing is certain, it was ONE of those things and it was fixed by the rewire. Can't say enough good things about our Chevy dealer: they took it in every time we experienced the problem, sometimes for several days, and even gave us a loaner car while they had it. Now it DID take about 7 trips over a year's time, but it is NOW fixed on their dime. Not too bad considering our Tahoe has 102,000 miles on it!

From what I have read with most people experiencing the limp mode issue on General Motors vehicles: 99% of the time it is this connection from the computer to the TB that is the problem. Whether a crack in the wiring, or a bad connection, this is it. GM is supplying dealers (or ours at least) with updated versions of this entire line, including revised connectors. Anyone scratching their heads about this dreaded problem should try this solution.

 

[VikingFan]

Holy Cow!!!! Glad it's fixed! Maybe this could get stickied?
This is a 2007 5.3 4x2?

 

[TahoeLTZ]

'07 Tahoe 4WD LTZ...