transmission shifting

2006 HUMMER H3
98 MILES • 5 CYL • 4WD
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ROBWHITE
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I have a 2006 Hummer H3. Last week the transmission started shifting only at high rpms 3000 plus. Transmission fluid has been changed every 30k, currently has 98000 on it.
Mar 26, 2011 at 4:48 PM
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FACTORYJACK
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Is the check engine light on, does it complete shifting through all four gears, and is the shifting more soft/harsh then normal?
Mar 26, 2011 at 5:46 PM
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ROBWHITE
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no check engine light on. sometimes it will shift to 4th but not all the time, depends on speeed and rpm. the shifting sounds normal.
Mar 26, 2011 at 6:57 PM
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FACTORYJACK
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Check and clean the mass air flow sensor hot wires, especially if it has an aftermarket oiled air filter(e.g. K&N). If it were possible, I would recommend checking and clearing the shift adapts, that would require a scan tool. I will include a general diagnostic chart for inaccurate shift points.
Mar 27, 2011 at 3:53 PM
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FACTORYJACK
  • ✓ASE Certified Mechanic
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  • ASE Certified Mechanic
The chart I mentioned.
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Mar 27, 2011 at 3:54 PM
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