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Document ID: 1527156
#04-06-04-040: Idle Instability, Low or Rough Idle with
Electronic Throttle Control (Clean
Throttle Body) - (Jun 14,
2004)
Condition
Some owners may comment on an idle instability, low idle speed or rough idle.
Cause
Condition may be caused by deposits in the throttle body bore.
Correction
Clean throttle body bore and throttle valve plate of carbon using a shop rag and an appropriate cleaner.
Refer to Engine Controls Repair Procedures - Throttle Body Cleaning Procedure. This procedure may be
performed at any mileage necessary. Check to determine if the PCM calibration has been previously
updated to one that includes the update for throttle body coking. For 2003 model year vehicles, look in the
operating system portion of the calibration. For 2000-2002 model year vehicles, look in the engine portion
of the calibration. If not, then update the PCM calibration to the latest calibration.
Warranty Information
For vehicles repaired under warranty, use:
Subject: Idle Instability, Low or Rough Idle with Electronic Throttle Control
(Clean Throttle Body)
Models: 2002-2003 Cadillac Escalade, Escalade EXT
2000-2003 Chevrolet Silverado, Suburban, Tahoe
2002-2003 Chevrolet Avalanche
2000-2003 GMC Sierra, Yukon, Yukon XL
2003 Hummer H2
with 4.8L, 5.3L or 6.0L V8 Engine (VINs V, T, Z, N, U - RPOs LR4, LM7, L59, LQ9,
LQ4)
and Electronic Throttle Control
Labor Operation Description Labor Time
J5480 Throttle Body - Clean and Adjust 0.2 hr
Add:
To Reprogram PCM 0.4 hr
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a
vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and
safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that
condition. See your GM dealer for information on whether your vehicle may benefit from the information.
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I was going to suggest the idle control valve, but its buot into the throttle body, so its not serviceable if it goes bad. I would replace the throttle body, instead of cleaning it
