Voltage Signal: Description and Operation

PURPOSE
The Powertrain Control Module (PCM) continuously monitors battery voltage inputs, and since battery voltage always fluctuates, the PCM will constantly be making changes to the injector pulse width and generator field.

OPERATION
The PCM monitors battery voltage to determine the proper injector pulse width and to control the generator field voltage. If the PCM sees low battery voltage, it will increase the injector pulse width to compensate for lack of voltage which could cause a lean air/fuel mixture.

A higher voltage signal will be sent to the generator field so that the generator will increase its charging output to the battery. When the generator increases its charging rate it will bring the battery up to its normal state of charge.

Once the battery is fully charged, the PCM reduces the injector pulse width so that the air/fuel mixture doesn't go excessively rich.