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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 102 (Engine Controls - Self-Diagnostics - 3.5L) >> Diagnostic Tests >> DTC P0650: Malfunction Indicator Light Control Circuit >> Circuit Description

Circuit Description

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue and 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

Ignition voltage is supplied directly to the Malfunction Indicator Light (MIL). The Powertrain Control Module (PCM) controls the MIL by grounding the control circuit via an internal solid state device called a driver. The primary function of the driver is to supply the ground circuit. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component on, voltage of the control circuit should be near zero volts. When the PCM is commanding a component off, voltage potential of the circuit should be near battery voltage. If the fault detection circuit senses a voltage other than what is expected, this DTC will set.