Amazon Printed-Books & Kindle: www.amazon.com Google Play Android APPs: play.google.com Amazon Video DVDs: www.amazon.com Barnes & Noble Nook: www.barnesandnoble.com Apple iTunes iPad: itunes.apple.com Automotive Robo Tech was called to a shop with a 2005 GMC G3500 and a 6.0 liter engine, experiencing a high or low idle with a code P0507, meaning Idle air control system RPM higher than expected stored in memory. This was a drive-by-wire system, so the throttle body controls the idle speed. At the request of the shops head mechanic, the shop swapped the throttle body from another 6.0 liter engine that was available, but to no avail. It did not work. It was then that the shop decided to call me in for assistance. As soon as I got into the shop, I devised a plan of attack for speed. I know that the throttle body was probably not the issue. I was more interested in the dual TPS sensor relationship to the idle control. The accelerator position sensor was also a person of interest. So then I decided to scan the vehicle for codes. As soon as I did, a P0507 popped on screen. Ok, this matched what the shop said. As I started the vehicle, I also experienced the main complaint of a high and low idle condition. Both throttle bodies were actually very clean, so it wasn’t an issue of de-carbonizing the throttle body. So, I then decided to perform a bi-direction control of the idle speed. By then the idle problem was not happening. Upon actuating the bi-directional control of the …
Source:
http://bookstokindle.com/blog/2013/01/05/chevys-g3500-throttle-and-hum/