Mechanics

TRANSMISSION SHIFTING

2006 Hummer H3 • 5 cylinder 4WD • 98 miles

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.
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Robwhite
March 26, 2011.



Is the check engine light on, does it complete shifting through all four gears, and is the shifting more soft/harsh then normal?


Factoryjack
Mar 26, 2011.
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.


Tiny
Robwhite
Mar 26, 2011.
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.


Factoryjack
Mar 27, 2011.
The chart I mentioned.


Factoryjack
Mar 27, 2011.