1994 Ford code 538 Insufficient RPM change during KOER Dyna

I get the code 538, description "Insufficient RPM change during KOER Dynamic Response Test." What does this mean? Should I fix it? how? It is a 1994 Ford, 7.5 liter gas engine in an RV, 44,000 miles. 538 is the only code, I checked 3 times, always came up with 538. Thanks

That code in not important. All it means is the accelerator was not pushed all the way to the floor during the "goose" portion of the engine running test.