Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Both of these codes are related and both point to a problem with the Transmission Fluid Pressure Switch Assembly. This switch is located inside the transmission side cover attached to the valve body. This very well could be related to the recent fluid and filter service. This code will set when there is a rapid change in pressure (like when fluid is drained and then refilled- pressure goes from low to high very quickly). It can also set if pressure is too low or too high (under-filled/over-filled). So, first, check the fluid level. If the level is good, I would recommend clearing the codes by removing the NEG cable from the battery for 5 minutes, as this could just be a byproduct of the recent service. If the code returns, then you'll need to look into the TFP switch as it may have been damaged due to the fluid service. If you found this answer helpful, please help me by leaving a rating using the "stars" at the top of the page or click 'accept'.Rating or accepting my answer does not cost you extra. It allows me to be credited for this Q&A.