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Home >> Chevrolet >> 2001 >> Camaro Base, 2D Convertible, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 7 (Engine Control System Self-Diagnostics - 5.7L) >> Diagnostic Tests >> DTC P1637: Generator "L" Terminal Circuit ("F" Body) >> Circuit Description

Circuit Description

WARNING: This page is about a different car, the 2000 Pontiac Firebird, 2000 Chevrolet Corvette, and 2000 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.

PCM applies ignition voltage to generator "L" terminal circuit. A small amount of current flows from this circuit through the generator windings to ground to create a magnetic field which starts the generator process. When generator is at operating speed and producing voltage, a solid state switch for the "L" terminal circuit in the generator opens and the PCM detects that the initial start-up current flow has stopped.

PCM expects to detect low voltage on "L" terminal circuit prior to the generator rotating at operating speed and conversely expects that circuit to be at ignition voltage potential when generator is operational. When PCM detects a fault (circuit shorted to ground or circuit shorted to voltage), the BATTERY light will illuminate.

DTC will set when PCM detects an improper voltage on generator "L" terminal circuit.