Engine Controls - Run-On With Ignition OFF
90buick01Bulletin 89-6D-4
Date Nov., '89
Ref. No. 89-256-6D
Corp. Ref. No. 906401
SUBJECT: ENGINE RUN-ON WHEN IGNITION SWITCH IS TURNED OFF
MODELS AFFECTED: 1988-1989 LESABRES AND ELECTRA/PARK AVENUES EQUIPPED WITH 3800 ENGINES
If a condition is encountered of engine run-on with the ignition switch turned off on the above models with 3800 engines, proceed with the following correction.
Inspect the MAF/TPS wiring branch at the back of the generator. In some cases the branch was wedged below the "B-plus" (BAT Terminal) bolt on the back of the generator (see attached figures).
The "B-plus" (BAT Terminal) bolt could be aligned with the conduit slit and contacted the wiring directly - eventually rubbing through. The wire contacted would be the ignition feed to the mass air flow sensor (pink with black stripe, CKT439) which could back-fed the ignition switch to keep the car running.
This condition can be corrected by removing the branch from the underside of the "B-plus" (BAT Terminal) connection, repairing as necessary, and routing it above the "B-plus" (BAT Teminal).