Powertrain Management: Description and Operation
ACRONYMS AND DEFINITIONSNOTE: This acronyms and definitions listing contains technical terms applicable to Ford Motor Company products. It is not intended to be an all-inclusive dictionary of components and their functions. If a detailed description of a particular system or component is desired, refer to Computers and Control Systems or refer to the applicable Vehicle System for the specific vehicle being repaired.
4WD: Four Wheel Drive
ABS: Anti-lock Brake System
A/C: Air Conditioning
A/CC: Air Conditioning Clutch
A/D: Analog-to-Digital. Analog-to-Digital signal conversion.
API: American Petroleum Institute
APP: Accelerator Pedal Position
ATF: Automatic Transmission Fluid
BARO: Barometric Pressure. A variable capacitance sensor which, when supplied with a 5-volt reference signal from the PCM, produces a linear analog voltage signal indicating atmospheric pressure.
BJB: Battery Junction Box
BPA: Brake Pressure Applied
BPP: Brake Pedal Position
BTDC: Before Top Dead Center
CAC: Charge Air Cooler. A heat exchanger mounted in the charge air path between the turbocharger and engine intake manifold. The CAC reduces the charge air temperature by transfering heat from the charge air to a cooling medium (usually air).
CAN: Controller Area Network. This is a SAE J1939 high speed communication link. CAN 1 is a public communications network between the vehicle modules and the PCM. CAN 2 is a private communications network between the PCM and the fuel injector control module (FICM).
CARB: California Air Resources Board
CCM: Comprehensive Component Monitor
Cetane number: 1. The auto-ignition quality of diesel fuel. 2. A rating applied to diesel fuel similar to octane rating for gasoline. 3. A measure of how readily diesel fuel starts to burn (auto ignites) at high compression temperature. Diesel fuel with a high cetane number auto-ignites shortly after injection into the combustion chamber. Therefore, it has a short ignition delay time. Diesel fuel with a low cetane number resists auto-ignition. Therefore, it has a longer ignition delay time.
CJB: Central Junction Box
CKP: Crankshaft Position
Closed loop operation: A system that uses a sensor to provide feedback to the PCM. The PCM uses the sensor to continuously monitor variables and adjust to match engine requirements.
CMP: Camshaft Position
CPP: Clutch Pedal Position
DEPM: Diesel Engine Power Monitor
DLC: Data Link Connector
DMM: Digital Multimeter
DTC: Diagnostic Trouble Code
ECM: Electronic Control Module
ECT: Engine Coolant Temperature
EEC: Electronic Engine Control
EEPROM: Electronically Erasable Programmable Read Only Memory
EGR: Exhaust Gas Recirculation. A process in which a small amount of exhaust gas is routed into the combustion chamber.
EOT: Engine Oil Temperature
EP: Exhaust Pressure
EPA: Environmental Protection Agency
ESOF: Electronic Shift-On-The-Fly
FICM: Fuel Injector Control Module. An electronic microprocessor that monitors and controls injector performance.
FLI: Fuel Level Input
FMEM: Failure Mode Effects Management. Operating strategy that maintains limited vehicle function in the event of a PCM or EEC component failure.
FP: Fuel Pump
FPM: Fuel Pump Monitor
FSS: Fan Speed Sensor
GPCM: Glow Plug Control Module
GPIL: Glow Plug Indicator Lamp
GPM: Glow Plug Monitor
GVWR: Gross Vehicle Weight Rating
IAT: Intake Air Temperature
IC: Integrated Circuit. A small semi-conductor device capable of many separate circuit functions.
ICP: Injection Control Pressure. High lube oil pressure generated by a high pressure pump/pressure regulator used to hydraulically actuate the fuel injectors.
IFS: Inertia Fuel Shutoff
IM: Inspection Maintenance
IPR: Injection Pressure Regulator. A pulse width modulated (PWM) regulator valve, controlled by the PCM, that controls the injection control pressure.
ISO: International Standards Organization
KAM: Keep Alive Memory. A portion of the memory within the PCM that must have power even when the vehicle is not operating.
KAPWR: Keep Alive Power. A dedicated and unswitched power circuit that maintains the KAM.
km/h: Kilometers per hour
KOEO: Key On Engine Off
KOER: Key On Engine Running
kPa: Kilopascal
L: Liter
LB-ft: Pounds of force per foot
MAF: Mass Air Flow. Intake air mass flow before the turbocharger.
MAP: Manifold Absolute Pressure. Intake air manifold pressure (boost pressure).
MFDES: Mass Fuel Desired
MIL: Malfunction Indicator Lamp
mm: Millimeter
MPH: Miles per hour
MSOF: Manual Shift-On-The-Fly
OASIS: On-line Automotive Service Information System
OBD: On Board Diagnostics. A system that monitors the PCM input and output control signals.
OD: Overdrive
Open Loop Operation: An operating condition based on instructions not modified by PCM feedback.
OSC: Output State Control
OSR: On-Board System Readiness
OSS: Output Shaft Speed
PATS: Passive Anti-Theft System
PBA: Parking Brake Applied
PCM: Powertrain Control Module. An electronic microprocessor that monitors and controls engine performance, exhaust emissions, and vehicle system performance (speed control, transmission control, and starter engagement). The PCM provides diagnostic information for engine and vehicle systems and can be programmed at different levels for engine protection, warning and shutdown.
PID: Parameter Identification
PTO: Power Take Off. An accessory output, usually from the transmission, used to operate a hydraulic pump for a special auxiliary feature (such as garbage packing or lift equipment).
PTS: Professional Technician Society
PWM: Pulse Width Modulation. The time that an actuator, such as an injector, remains energized.
RAM: Random Access Memory. Computer memory that stores information. Information can be written to and read from RAM. Input information (such as current engine speed or temperature) can be stored in RAM to be compared to values stored in the read only memory (ROM). All memory in RAM is lost when the key is turned to the off position.
ROM: Read Only Memory. Computer memory that stores permanent information for calibration tables and operating strategies. Permanently stored information in ROM cannot be changed or lost by turning the engine off or when PCM power is interrupted.
RPM: Revolutions Per Minute
SAE: Society of Automotive Engineers
SIG RTN: Signal Return. The common ground wire to the PCM for the sensors.
TCM: Transmission Control Module
TCS: Transmission Control Switch
TDC: Top Dead Center. The uppermost position of the piston during the stroke.
TFT: Transmission Fluid Temperature
TSB: Technical Service Bulletin. Notifies technician of any known vehicle concerns, procedures, or general repair information.
VBAT: Battery Voltage
VDF: Visctronic Drive Fan
VECI: Vehicle Emission Control Information
VGT: Variable Geometry Turbo
VIN: Vehicle Identification Number
VREF: Reference Voltage. A 5-volt reference voltage supplied by the PCM to operate various engine sensors.
VSS: Vehicle Speed Sensor. A magnetic pickup device that generates an AC signal that is proportional to the vehicle speed.
WIF: Water In Fuel
WOT: Wide Open Throttle. A condition of maximum airflow through the throttle body.
VCM: Vehicle Communication Module
VID: Vehicle Identification
VSF: Variable Speed Fan