Trouble code help

Does anyone know what I need to check or replace for a trouble code 42 (electronic spark timing) in a 92 z28?

I'd clear the code first then see if it reoccures. After clearing the code, I'd make sure the advance wire is cleaned at the connectors and seated well with dielectric grease in the connector. If it still does that, next thing I'd check is the module in the distributor.

I've cleared it and it does come back. I'll check the connectors and I bought a module today to install tomorrow. Thanks