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  1. #1

    Default Reduced engine power help

    This is my first post so hello to all. I have been having a problem with my 04 silverado 2500 HD for the past 8 months . My truck has been going into reduced engine power on several occasions and i want to know if anyone else has experienced this problem. I have been to the my local dealer who has changed the throttle sensor, and reterminated the wires to the tps plug.But the problem still exists.I am considering going to another dealer. I have purchaced a mac tools et105 that has been pulling some codes. So far i have p2135,p0220,p1516, and p2101.Does anyone know if there is a TSB on this year truck? Please help this is driving me nuts. Thanks for any help in advance.
    Last edited by NHRASST1974; 05-10-2010 at 10:01 AM.

  2. #2


    Try this thread. He seems to be having the same problems as you. Good luck and welcome to the site

  3. #3
    Master Mechanic daddytech's Avatar
    Join Date
    Mar 2008
    Portland TN


    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.

    Complete the current SI diagnostics for any symptoms or trouble codes found. If a intermittent T/P or TAC module type code is occurring complete the inspections below.

    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, but installing this pigtail connector may cause other intermittent TAC module/TP codes at a later date. If this pigtail must be used, please follow the SI procedures for Splicing Copper Wire Using Splice Sleeves. (the proper Kent-Moore crimping tool must be used for this repair)

    Most common cause of 1516 is a weak or dead battery.
    hope this helps

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