ALFA ROMEO 156 OWNER'S MANUAL Pdf Download. View and Download Alfa Romeo 156 owner's manual online. 156 Automobile pdf manual download. Also for: Alfa 156. If the warning light comes on again the next time the engine is started, contact Alfa Romeo Authorized Services. – Car heavy duty (e.g. towing a trailer uphill or car fully loaded): slow down and, if the warning light stays on Alfa Romeo Alfa 156 Service and Repair Manuals. Alfa Romeo Alfa 156. The Alfa Romeo 156 is a compact executive car produced by the Italian automobile manufacturer Alfa Romeo from 1997 to 2007. It was introduced at the 1997 Frankfurt Motor Show as the replacement for the Alfa Romeo 155.