Code 51 and/or 71
WARNING: This page is about a different car, the 1988 Buick Riviera and 1988 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
Go to Chart A9. If no trouble is found while performing tests on Chart A9, do not go to chart F. Instead go to Chart G Solenoid Valves. Perform solenoid valve test for left front valves. If no trouble is found, replace ECBM.