Circuit Description
WARNING: This page is about a different car, the 1996 Pontiac Bonneville, 1996 Oldsmobile LSS, 1996 Oldsmobile Eighty-Eight, and 1996 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
Output Driver Modules (ODM) are used by PCM to turn on current-driven devices needed to control various engine and transaxle functions. Each ODM can control up to 7 outputs, including fuel pump Pulse Width Modulation (PWM) driver circuit, by supplying ground to device PCM is commanding on. ODMs can diagnose each circuit individually. If ODM "A" output 3 (fuel pump PWM driver circuit) detects an improper voltage level, P1643 is set.