Powertrain Control Hardware
Powertrain Control Hardware
Powertrain Control Module (PCM)
The center of the electronic engine control (EEC) system is a microprocessor called the PCM. The PCM receives input from sensors and other electronic components (switches relays). Based on the information received and programmed into its memory the PCM generates output signals to control various relays solenoids and actuators. There are several different types of PCMs in use for this model year. Refer to the Vehicle PCM Application Table below for PCM types and their applications.
PCM Locations
Note: For PCM Removal and Installation procedures refer to Electronic Engine Controls.
^ Focus - passenger side behind the kick panel.
^ Five Hundred Freestyle Montego - engine compartment driver side mounted to the cowl.
^ Taurus Sable Freestar Monterey - behind the glove compartment (access from the engine compartment dash panel) on the passenger side.
^ Mustang - front of engine compartment passenger side near fender under the battery junction box.
^ Crown Victoria Grand Marquis Town Car - engine compartment driver side~ fender mounted.
^ LS Thunderbird Explorer Mountaineer Aviator - passenger side near side cowl~ behind the glove compartment.
^ Ford GT - engine compartment driver side behind the driver seat quarter panel mounted.
^ Escape Mariner Explorer Sport Trac Ranger - behind the instrument panel (cowl) center to both driver and passenger sides (access from the engine compartment).
^ Expedition Navigator F-Series F-Super Duty - passenger side of the engine compartment mounted to the cowl.
^ Excursion - lower dash panel on the driver side.
^ E-Series - engine compartment driver side near the cowl (access from the engine compartment).
Fuel Injector Control Module
The fuel injector control module (FICM) is used to control the dual-injection fuel delivery system for gasoline engines. Based on an input from the PCM the FICM will control either single or dual-injection modes.
Fuel Pump Driver Module (FPDM)
Note: For the Thunderbird and LS the FPDM functions are incorporated in the rear electronic module (REM). The fuel pump operation is the same as for applications using the stand-alone FPDM. The REM will however communicate diagnostic information through the communication link instead of using a fuel pump monitor (FPM) circuit.
Note: The Ford GT uses 2 FPDMs to control fuel for the dual-injection fuel delivery system. The PCM will output only one fuel pump duty cycle which is used by both pumps. The PCM will individually monitor the FPDMs through their fuel pump monitor circuits. Both FPDMs are mounted on the same bracket. The FPDM mounted in the upper position on the bracket is referred to as FPDM and the FPDM mounted in the lower position is referred to as FPDM2.
The FPDM receives a duty cycle signal from the PCM and controls the fuel pump operation in relation to this duty cycle. This results in variable speed fuel pump operation. The FPDM sends diagnostic information to the PCM on the fuel pump monitor circuit.
Keep Alive Memory (KAM)
The PCM stores information in KAM (a memory integrated circuit chip) about vehicle operating conditions and then uses this information to compensate for component variability. KAM remains powered when the ignition switch is off so that this information is not lost.
Hardware Limited Operation Strategy (KLOS)
This system of special circuitry provides minimal engine operation should the PCM (mainly the central processing unit [CPU] or EEPROM) stop functioning correctly. All modes of self-test are not functional at this time. Electronic hardware is in control of the system while in KLOS.
HLOS Allowable Output Functions:
^ Spark output controlled directly by the CKP signal.
^ Fixed fuel pulse width synchronized with the CKP signal.
^ Fuel pump relay energized.
^ Idle speed control output signal functional.
HLOS Disabled Outputs To Default State:
^ EGR solenoids.
^ No torque converter clutch lock-up.
Integrated Electronic Ignition System
The integrated electronic ignition (El) system consists of a crankshaft position (CKP) sensor coil pack(s) connecting wiring and PCM. The coil on plug (COP) integrated El system uses a separate coil for each spark plug and each coil is mounted directly onto the plug. The COP integrated El system eliminates the need for spark plug wires but does require input from the camshafi position (CMP) sensor.
Power and Ground Signals
Electronic Throttle Control Reference Voltage (ETCREF)
ETCREF is a consistent positive voltage (5.0 volts 0.5) supplied by the powertrain control module (PCM). ETCREF is internally bussed within the PCM and is specifically dedicated to the accelerator pedal position (APP) sensor and the electronic throttle body (ETB) throttle position (TP) sensor.
Electronic Throttle Control Return (ETCRTN)
ETCRTN is a return path for ETCREF and is internally bussed within the PCM. ETCRTN is specifically dedicated to the accelerator pedal position (APP) sensor and the electronic throttle body (ETB) throttle position (TP) sensor.
Gold Plated Pins
Note: Gold plated terminals should only be replaced with new gold plated terminals.
Some engine control hardware has gold plated pins within the connectors and mating harness connectors to improve electrical stability for low current draw circuits and to enhance corrosion resistance. The electronic engine control (EEC) components equipped with gold terminals vary by vehicle application.
Keep Alive Power (KAPWR)
KAPWR provide a constant voltage input independent of ignition switch state to the PCM. This voltage is used by the PCM to maintain the keep alive memory (KAM).
Mass Air Flow (MAF) Return
The mass air flow return (MAF RTN) is a dedicated analog signal return from the MAF sensor. It serves as a ground offset for the analog voltage differential input by the MAF sensor to the PCM.
Power Ground (PWR GND)
The PWR GND circuit(s) is directly connected to the battery negative terminal. PWR GND provides a return path for the PCM VPWR circuits.
Signal Return (SIG RTN)
SIG RTN is a dedicated return path for VREF applied components.
Vehicle Buffered Power (VBPWR)
Vehicle buffered power (VBPWR) is a regulated voltage supplied by the PCM to vehicle sensors. These sensors require a constant 12 volts for operation and cannot withstand VPWR voltage variations. VBPWR is regulated to VPWR minus 1.5 volts and is also current limited to protect the sensors.
Vehicle Power (VPWR)
VPWR is the primary source of PCM power. VPWR is switched through the EEC power relay and is controlled by the ignition switch.
Vehicle Reference Voltage (VREF)
VREF is a consistent positive voltage (5.0 volts 0.5) provided by the PCM. VREF is typically used by 3-wire sensors and some digital input signals.