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Home >> Jeep >> 2008 >> Commander 2WD V6-3.7L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Engine Control Module >> Description and Operation >> Powertrain Control Module - Operation >> Ignition Circuit Sense
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Ignition Circuit Sense







IGNITION CIRCUIT SENSE

The ignition circuit sense input tells the PCM the ignition switch has energized the ignition circuit.

Battery voltage is also supplied to the PCM through the ignition switch when the ignition is in the RUN or START position. This is referred to as the "ignition sense" circuit and is used to "wake up" the PCM. Voltage on the ignition input can be as low as 6 volts and the PCM will still function. Voltage is supplied to this circuit to power the PCM's 8-volt regulator and to allow the PCM to perform fuel, ignition and emissions control functions.