'02 Jetta TDI - MIL light and code 1705A

I have an '02 Jetta TDI and the MIL light came on a few days ago. I made an appointment wil my Diesel mecahnic later this week but can't get in before then.

I figured the light was just a glow plug that needed replacing, but I got the code from a non-diesel shop and the guy told me it was 1705A, which he wasn't able to identify. I did an internet search and found that code p1705 means:

Gear/Ratio Monitoring Adaptation limit reached

What does that mean and should I limit/stop my driving until getting to the mechanic? I know enough that the P means powertrain and that the 7 means transimission. It's a manual transmission and I have not been experiencing any shifting problems.

Also, the code I got was 1705A. I can't find any reference to the A.

Any help would be appreciated.