I have seen a dirty throttle bore cause this issue. Please follow this guide to help this the problem.
Here is the book info on it
follow this info,A vehicle may be brought into the dealer for a reduced power message, and DTCs P0120, P0220, P1516, P2101, or P2135.
The Throttle Actuator Control (TAC) / throttle body type trouble codes, may be caused by a loose wiring crimp at the throttle body connector, or a broken throttle body circuit.Inspect all related throttle body terminals for a loose wiring crimp. The loose crimp may be difficult to find, and the poor connection will be between the terminal and the copper strands of the wire. Wiggle test the individual throttle body circuits to see if the concern can be duplicated.
Inspect the related circuits for broken wires inside the insulation. The outer wire insulation may look fine, but the internal copper strands may be partially broken. Breaks in the wires usually occur within 1 to 4 inches of the throttle body connector. Wiggle testing may also induce a trouble code to set.
On C/K trucks complete SI procedures for voltage drop on grounds G103 and G104. Grounds G103 or G104 may be loose or corroded. If a terminal crimp or a broken wire has been found, repair or replace only the circuits involved. There is a throttle body pigtail connector available through GMSPO,
You wont be able to see anything by looking at it move the wiring and connector up/down with you hand and see if the light goes on/off. It states this in the info I gave, loose crimps and broken stands are hard to find, you can also run your finger nail down each wire to find the broken/dead spot.post back with any other questions.
Please let us know what you find.
Tuesday, February 3rd, 2009 AT 9:15 AM