Allison Transmission Questions HI, My Gulfsteam is giving me a noshift light and down shifts when I hit a hard bump. Bridges are one that causes it to do this. I have reset the codes a couple of time but didn't know what the code indicated. Do you have a soft copy of the codes that are displayed or where I can get them. i suspect an electrical problem and have checked battery terminlas etc. to no avail. Thanks..Don Sr.