2005 sonata why is my transmission shift hard in second to third?

You can only diagnose problems like yours with a pro grade scan tool computer as opposed to a generic 'code reader'. It may be the shift solenoid or a computer data issue. A 5 grand scan tool can instruct shift solenoids to operate and verify that they have. They can also diagnose issues with the data transfers. The Durango works entirely by computer instructions from module to module.

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Shifting problems are a known issue.

https://www.google.com/search?q=2005+Dodge+Durango+not+shifting+into+third+gear

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There could be several reasons why your 2005 Dodge Magnum is experiencing problems with shifting from second to third gear and then suddenly hitting reverse, including:

1. Transmission Fluid Level: Low transmission fluid level can cause erratic shifting, slipping, or stalling in your vehicle. Make sure to check your transmission fluid level and add if necessary.
2. Shift Solenoid: A faulty shift solenoid can cause problems with shifting in your transmission. The solenoids control the flow of transmission fluid through the valve body, which controls the shifting of gears. If the shift solenoid is failing or has failed, it can cause the transmission to slip, shift erratically, or get stuck in a gear.
3. Transmission Pump: The transmission pump is responsible for pumping transmission fluid through the transmission and to the torque converter. If the pump is failing, it may not be able to pump fluid properly, leading to problems with shifting and slippage.
4. Valve Body: The valve body controls the flow of transmission fluid through the transmission and directs the shifting of gears. If the valve body is failing, it can cause the transmission to shift erratically or get stuck in a gear.
5. Transmission Control Module (TCM): The TCM is responsible for controlling the transmission's shifting and overall performance. If the TCM is failing, it can cause the transmission to shift erratically or get stuck in a gear.

It's best to have a qualified mechanic diagnose and repair the issue as they will have the necessary tools and expertise to properly diagnose and fix the issue.

see if this link helps you out.... My 2004 chevy trailblazer won shift from second to third gear Google Search

How To Rebuild A 4L60E Automatic Transmission - YouTube

? 13:19
https://www.youtube.com/watch?v=JpmJtuVrdWk
Mar 16, 2011 - Uploaded by Nick Stageberg
How To Rebuild A 4L60E Automatic Transmission ... Also here is a link to some common break/fixes that may require a rebuild:... GMC canyon, envoy, safari savana, sierra Sonoma, Yukon, ....Great video, my 96 sierra 4x4 when shifting into high gear motor races as if nothing is there........................always ...

30 Common 4L60E Transmission Problems & Repair ...

www.twincharlotte.com/transmission-repair.../30-Common-4L60E-Trans...

Mar 18, 2011 - The 4L60-E is an automatic shift, four-speed overdrive, longitudinally...... 4l60e 2002 gmc 4x4 was not driven for 1 year,will not shift into 3rd or ... I have a 2005 GMC envoy 4x4 6 Cylinder I assume it is a 460LE Transmission.

Which engine/trans do you have?
Mileage?

it possible that your transmission is about to give out. So you might want to take it to a auto shop and have them check your transmission.

my 2004 chevy impala shifts hard when it warms up

Here is what the service manual says about the EPC solenoid, the processor looks at allot of different inputs to command the solenoids, such as Throttle Position Sensor, Vehicle Speed Sensors, Transmission Range Sensor and RPM signal, The PCM controls the shift patterns for the transmission. Electronic Pressure Control (EPC) Solenoid
The electronic pressure control (EPC) solenoid is located on the main control valve body and is controlled by the PCM. The EPC controls line pressure used to apply and release clutches and bands in the transmission.
The 2-3 shift solenoid is located on the main control valve body and is switched on and off by electrical signals from the PCM. The 2-3 shift solenoid activates the 2-3 shift valve which controls the automatic shifting between second and third gear. Second gear is established when the 2-3 shift solenoid is switched on. The 2-3 shift solenoid is switched off when vehicle speed increases and requires a second to third gear upshift.
The 3-4 shift solenoid is located on the main control valve body and is switched on and off by electrical signals from the PCM. The 3-4 shift solenoid activates the 3-4 shift valve which controls the automatic shifting between third and fourth gear. Third gear is established when the 3-4 solenoid is switched off. The 3-4 shift solenoid is switched on when vehicle speed increases and requires a third to fourth gear upshift.

need computerized check on transmission condition, they will let you know why this happening.

Valves likely hanging up in valve body. There is a kit made by TransGo that is works wonderful for the shifting/calibration issues - as long as there isn't something else failing within.