rcmedic

Here is another response from the Edmunds forum. Don't pay huge money for diagnostics...please read!!!! I finally found someone that fixed my YXL and fixed it right...The problem is the ground wires. My mechanic tightened one that he found loose and the other one the clamp was messed up so the ground wire was flopping around and not making a good connection. When he touched the ground wire he could hear the fuel pump going on and off and other things making noises. It was a $3 dollar clamp that fixed it...too bad I spent almost $2000 on diagnostics with the dealership that was trying to tell me I had a bad transfer case module as well as a bunch of other BS and another mechanic before I brought it to this guy. Make sure your mechanic checks all the grounds (I didn't know that there's more than one) and tightens them as well as making sure the clamps are in good condition. My clamp was broken causing a bad connection. So...it's a $3 part that caused this hellified problem! I'm just glad to have my vehicle back in good running condition...no thanks to the dealership or GMC!

Thank you Marc for the excellent write up. I have been fighting this battle on my 2005 Suburban 2500 4x4 LT for a little over a year now. True to claims, it has been intermittent. I long since replaced my knock sensors and the throttle pedal position sensor. Also true is the fact that I replaced (first) just the TPS on the throttle body, then the plug and harness for the TPS and then with the entire new throttle body assembly. The problem has continued unabated and also continues to occur completely at random. Sometimes the interval is very short, (sometimes only seconds) and other times very long, ( 1000 miles or more). After replacing the entire throttle body assembly and NOT correcting the problem, I took it to a local dealer to put it on their computer for assessment and re-calibrating/relearning etc. and all that was a bust too. (dealer charged me $120). The dealer told me that they would have to replace all of the parts that I already replaced "with Genuine GM pars" or they would be unable to do anything never mind make any guarantees. (their estimate for repairs was well north of $1000). I said no. I have spent countless hours researching this issue and thus far to no avail. You bring up a single point that I have not investigated "closely" and so my next step will be to address the grounding connections. Though I no longer do it for a living, I have been a mechanic virtually my entire life. Your detailed instructions are very good. Thank you. On a separate note, I have been needing some dielectric grease for some other projects anyway. Guess I will finally go buy some. Thanks again.