There are 2 owner-reported powertrain & transmission complaints for the 2004 Hummer H2in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
I WAS DRIVING HOME AT NIGHT AND ABOUT A MILE BEFORE I GOT HOME MY TRANSMISSION DIDN'T SEEM TO SHIFT AS SMOOTH AS IT USUALLY DOES AND WHEN I PARKED IN MY GARAGE I GOT OUT AND TRANSMISSION FLUID WAS DRIPPING OUT FROM UNDER MY H2 VERY QUICKLY AND BY THE NEXT HOUR IT HAD EVERY BIT RUN OUT AND HUGE PUDDLE OF TRANSMISSION FLUID WAS ALL OVER MY GARAGE FLOOR. I TOOK THE SKID PLATE OFF MY H2 AND THE TRANSMISSION LINE HAD A HOLE RUSTED THROUGH IT. HAD I BEEN ANOTHER FEW MILES AWAY FROM GETTING HOME THIS COULD HAVE DESTROYED MY TRANSMISSION AND POSSIBLY CAUSED ME TO WRECK.
GM 4L65-E OR 4L65E TRANSMISSION PROBLEM. ENGINE LIGHT HAS BEEN ON AND FREQUENTLY THE 4 SPEED AUTOMATIC TRANSMISSION LOSES FIRST AND FOURTH GEARS. WILL NOT AUTOMATICALLY DOWNSHIFT FROM THIRD TO SECOND (THIS CAN BE DONE MANUALLY - ONLY 2ND AND 3RD WORK THOUGH) - FEELS LIKE IT WILL NOT COME OUT OF DRIVE AUTOMATICALLY WHEN SLOWING ALL THE WAY TO A STOP. IT HAS BEEN ACTING ERRATIC FROM NORMAL TO PROBLEMATIC - ERROR CODE INDICATES 'TORQUE CONVERTER CLUTCH SOLENOID LOCK UP' A YOUTUBE VIDEO MIGHT DESCRIBE IT HERE: HTTP://WWW.YOUTUBE.COM/WATCH?V=5JEB0KPAN_G I COULD SEE WHERE IT VERY WELL COULD CAUSE AN ACCIDENT BECAUSE THE TRANSMISSION SLIPS WHEN IT DECIDES IT WANTS TO. *TR
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026