Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

EGR System - Check Engine Light On/Code 53 Set

DCS NO. 84-04
SUBJECT: 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