2023 Yukon 3.0 Duramax - Speed limitation - Error Message PO 0747

[KCRetired]

Received a Reduced Acceleration Notice while driving at 70 mph, Diagnostic readout at Auto Zone gave diagnostic of PO 0747, Solenoid on Transmission stuck open. Read on other sites that this problem may be more than a "solenoid" issue. Car at the dealer now.. Anyone have information on this issue,? any technical Bulletins? On road trip vacation. trying to plan for easy or extensive repair..

 

[operator5362flink]

Condition​	Some customers may comment that the MIL is illuminated, and the transmission has defaulted and is not shifting. Technicians may find during diagnosis that the TCM has set DTC P0747, and the transmission has defaulted to 5th gear.​
Cause​	This condition may be caused by the Transmission Control Valve Body that has most likely failed causing the P0747 to set and the default condition.​
Information ​	In most cases of DTC P0747, the control valve may only need replacement.​

https://static.nhtsa.gov/odi/tsbs/2024/MC-11001761-0001.pdf

A later update to that bulletin includes your model.

 

[operator5362flink]

Unfortunately, the part is on a national backorder. See this thread: https://www.tahoeyukonforum.com/threads/transmission-valve-body-no-parts-to-be-found.153610/

 

[Miami-Dade]

@KCRetired Moved you here from Site News.
Welcome from Miami&NYC!