Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I don't think maintenance will help with the resistance feature not working.
But, what is the problem?
And, is there any error code showing on the console at any time?
Resistance failures are either
1. operator error
2. defective console (unlikely)
3. defective resistance motor controller board
4. defective resistance motor
5. defective linkage (unlikely).
Let me know more about the problem, please.