Outputs

AIR CONDITIONING (A/C) CLUTCH RELAY-PCM OUTPUT

Power Distribution Center (PDC):

The A/C relay is located in the Power Distribution Center (PDC). The PDC is located in the engine compartment. Refer to label on PDC cover for relay location,

The Powertrain Control Module (PCM) activates the A/C compressor through the A/C clutch relay. The PCM regulates A/C compressor operation by switching the ground circuit for the A/C clutch relay on and off.

When the PCM receives a request for A/C from A/C evaporator switch, it will adjust idle air control (IAC) motor position. This is done to increase idle speed. The PCM will then activate the A/C clutch through the A/C clutch relay. The PCM adjusts idle air control (IAC) stepper motor position to compensate for increased engine load from the A/C compressor.

By switching the ground path for the relay on and off; the PCM is able to cycle the A/C compressor clutch. This is based on changes in engine operating conditions. The PCM will also de-energize the relay if coolant temperature exceeds 125°C (257°F).

AUTO SHUTDOWN (ASD) RELAY-PCM OUTPUT
The ASD relay is located in the Power Distribution Center (PDC).

The ASD supplies battery voltage to the fuel injectors and ignition coil(s). With certain emissions packages it also supplies voltage to the oxygen sensor heating elements. The ground circuit for the coil in the ASD relay is controlled by the Powertrain Control Module (PCM). The PCM operates the relay by switching the ground circuit on and off.

CCD BUS (+A) CIRCUITS-PCM OUTPUTS
The Powertrain Control Module (PCM) sends certain output signals through the CCD bus circuits. These signals are used to control certain instrument panel located items and to determine certain identification numbers.

DATA LINK CONNECTOR-PCM INPUT AND OUTPUT

Data Link Connector Location:

The 16-way data link connector (diagnostic scan tool connector) links the Diagnostic Readout Box (DRB) scan tool or the Mopar Diagnostic System (MDS) with the Powertrain Control Module (PCM). The data link connector is located under the instrument panel to the left of the steering column. For operation of the DRB scan tool, refer to the appropriate Powertrain Diagnostic Procedures service manual.

DUTY CYCLE EVAP PURGE SOLENOID VALVE-PCM OUTPUT
Refer to Emission Control System for information.

FUEL INJECTORS-PCM OUTPUT

Fuel Rail And Injectors-4.0L 6-Cyl. Engine:

Fuel Rail And Injectors-2.5L 4-Cyl. Engine:

Six individual fuel injectors are used with the 4.0L 6-cylinder engine. Four individual fuel injectors are used with the 2.5L 4-cylinder engine. The fuel injectors are attached to the fuel rail.

The nozzle ends of the injectors are positioned into openings in the intake manifold just above the intake valve ports of the cylinder head. The engine wiring harness connector for each fuel injector is equipped with an attached numerical tag (INJ 1, INJ 2 etc.). This is used to identify each fuel injector.

The injectors are energized individually in a sequential order by the Powertrain Control Module (PCM). The PCM will adjust injector pulse width by switching the ground path to each individual injector on and off. Injector pulse width is the period of time that the injector is energized. The PCM will adjust injector pulse width based on various inputs it receives.

During start up, battery voltage is supplied to the injectors through the ASD relay. When the engine is operating, voltage is supplied by the charging system. The PCM determines injector pulse width based on various inputs.

FUEL PUMP RELAY-PCM OUTPUT
The fuel pump relay is located in the Power Distribution Center (PDC).

The PCM energizes the electric fuel pump through the fuel pump relay. Battery voltage is applied to the fuel pump relay when the ignition key is ON. The relay is energized when a ground signal is provided by the PCM.

The fuel pump will operate for approximately three seconds unless the engine is operating or the starter motor is engaged.

GENERATOR FIELD SOURCE (+)-PCM OUTPUT
This output from the Powertrain Control Module (PCM) regulates charging system voltage to the generator field source (+) circuit. The voltage range is 12.9 to 15.0 volts. Models of previous years had used the ASD relay (directly) to apply the 12 volt + power supply to the generator field source (+) circuit.

GENERATOR FIELD DRIVER (-)-PCM OUTPUT
This output from the Powertrain Control Module (PCM) regulates charging system ground control to the generator field driver (-) circuit.

GENERATOR LAMP-PCM OUTPUT
If the Powertrain Control Module (PCM) senses a low charging condition in the charging system, it will illuminate the generator lamp (if equipped) on the instrument panel. For example, during low idle with all accessories turned on, the lamp may momentarily go on.

IDLE AIR CONTROL (IAC) MOTOR-PCM OUTPUT
The IAC motor is mounted on the throttle body and is controlled by the Powertrain Control Module (PCM).

The throttle body has an air control passage that provides air for the engine at idle (the throttle plate is closed). The IAC motor pintle protrudes into the air control passage and regulates air flow through it. Based on various sensor inputs, the PCM adjusts engine idle speed by moving the IAC motor pintle in and out of the air control passage. The IAC motor is positioned when the ignition key is turned to the On position.

A (factory adjusted) set screw is used to mechanically limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the PCM.

IGNITION COIL-PCM OUTPUT
System voltage from the Automatic Shutdown (ASD) relay is supplied to the ignition coil positive terminal. The Powertrain Control Module (PCM) operates the ignition coil. Ignition timing is not adjustable. The PCM adjusts ignition timing to meet changing engine operating conditions.

Refer to Ignition System for additional information.

LEAK DETECTION PUMP-PCM OUTPUT
Certain engines with certain emissions packages are equipped with a leak detection pump (LDP). The LDP is activated through this PCM output. Refer to Emission Control System for additional information.

RADIATOR FAN RELAY-PCM OUTPUT
An electric radiator cooling fan is used with certain models/engines. It is controlled by the Powertrain Control Module (PCM) through the radiator fan relay. The relay is energized when coolant temperature is above 103°C (217°F). It will then de-energize when coolant temperature drops to 98°C (208°F).

The relay is located in the Power Distribution Center (PDC).

MALFUNCTION INDICATOR LAMP-ECM/PCM OUTPUT
Refer to Emission Control System for information.

SPEED CONTROL SOLENOIDS-PCM OUTPUT
Speed control operation is regulated by the Powertrain Control Module (PCM). The PCM controls the vacuum to the throttle actuator through the speed control vacuum and vent solenoids. Refer to Speed Control Information.

TACHOMETER-PCM OUTPUT
The Powertrain Control Module (PCM) supplies engine rpm values to the instrument cluster tachometer.