Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
ECU If I Recall Correctly.
VSS does have an input to the ECU, but does not determine what gear you should be in.
If it shifts but does not want to go over 30+ mph, then you are in Low Range. The linkage may have came loose or need adjusted.