EGR System - Check Engine Light On/Code 53 Set
DCS NO. 84-04SUBJECT: 1984 CODE 53 ON 4.1L, 3.8L, AND 3.0L ENGINES 9/20/83
TO: ALL BUICK DEALERS NEW VEHICLES MAY BE RECEIVED WITH A CHECK ENGINE LIGHT ON AND CODE 53 SET IN ECM MEMORY. IF THIS CONDITION EXISTS, IT IS MOST LIKELY DUE TO INCORRECTLY ROUTED OR DISCONNECTED VACUUM HOSES TO THE EGR VALVE. TO CORRECT, ENSURE THAT ALL ENGINE VACUUM HOSES ARE CONNECTED AS SHOWN ON THE EMISSION/TUNE-UP LABEL LOCATED JUST ABOVE THE RADIATOR.
J.D. MACK, MANAGER, TECHNICAL SERVICE - 9-20-83 JGD/GW