2007 Jeep Compass

Voltage Regulator

Print

Adjustment



Specific to:

Jeep Compass 2007-2009

Jeep Patriot 2007-2009

The amount of DC current produced by the alternator is controlled by the Electronic Voltage Regulator (EVR) circuitry contained within the PCM. This circuitry is connected in series with the second rotor field terminal and the alternator ground.

Voltage is regulated by cycling the ground path to control the strength of the rotor magnetic field. The EVR circuitry monitors system line voltage (B+). It then determines a target charging voltage. If sensed battery voltage is 0.5 volts or lower than the target voltage, the PCM uses Pulse Width Modulation (PWM) to ground the field winding until sensed battery voltage is 0.5 volts above target voltage. A circuit in the PCM cycles the ground side of the alternator field up to 100 times per second (100 Hz), but has the capability to ground the field control wire 100 percent of the time (full field) to achieve the target voltage. If the charging rate cannot be monitored (limp-in), a duty cycle of 25 percent is used by the PCM in order to have some alternator output.

No adjustment is necessary or possible.

Removal & Installation



Specific to:

Jeep Compass 2007-2009

Jeep Patriot 2007-2009

The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a voltage regulating circuit located within the Powertrain Control Module (PCM). The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.

 
label.common.footer.alt.autozoneLogo