Hi Eric,
Yes, the Google custom parameters that specifically auto-map from the e-Commerce extension are these:
gcp.prodid=._cprod (Product ID)
gcp.price=_csubtotal (Sub Total)
gcp.pname=_cprodname (Product Name)
gcp.pcat=_ccat (Category)
gcp.value=_cprice (Product Price)
but only on pages where the order ID is available (typically the order confirmation page). On other pages, the GCPs are not mapped or sent. If you want it to fire the GCPs on other pages, such as product or cart, you will have to manually map a variable (normally with a value of 'product' or 'cart') to google_custom_params.pagetype (available in the toolbox).
Additionally, other values outside of the GCPs are sent, such as product SKU and quantity, any time product IDs and their associated values are on a page, but these are a standard part of the tag and not part of the GCPs.