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Home >> Oldsmobile >> 1998 >> Regency >> Repair and Diagnosis >> External Pages >> Different car >> Section 7 (Engine Control Systems Tests W/Codes) >> Diagnostic Trouble Codes >> DTC P1643 - Fuel Pump Pulse Width Modulation PWM) Control Circuit >> Diagnostic Aids
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Diagnostic Aids

WARNING: This page is about a different car, the 1997 Pontiac Bonneville, 1997 Oldsmobile Regency, 1997 Oldsmobile LSS, 1997 Oldsmobile Eighty-Eight, and 1997 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.

Check for faulty connections or damaged harness. Disconnect PCM connector. Turn ignition on. Connect a DVOM between engine ground and PCM harness connector fuel pump PWM driver circuit. Observe DVOM while moving all related harness and connectors. A change in voltage display indicates fault location.

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