VECI Decal
Each vehicle has a VECI decal, located on the engine, containing emission control information that applies specifically to the vehicle and engine. The VECI decal shows the model year, engine displacement and rated horsepower.
Accelerator Pedal Position (APP) Sensor
The APP sensor is a 3-track potentiometer that is used to calculate driver demand for power based on the rotation angle of the accelerator pedal. The sensor receives a reference voltage from the powertrain control module (PCM) and provides a variable voltage signal directly proportional to the accelerator pedal position. The PCM uses the 3 APP sensor inputs to calculate the desired fuel quantity, injection timing, and the correct injection control pressure. A concern with the APP sensor illuminates the powertrain malfunction indicator (wrench). Normal engine operation is permitted if the PCM detects a concern on one of the 3 sensor signals. If the PCM detects a concern on two of the 3 sensor signals, the PCM only allows the engine to operate at idle.
Air Conditioning (A/C) Pressure Switch
The A/C pressure switch is used for additional A/C system pressure control. The A/C pressure switch is also referred to as the refrigerant containment switch.
For refrigerant containment control, the normally closed high pressure contacts open at a predetermined A/C head pressure. This turns off the A/C by opening the A/C demand circuit, preventing the A/C pressure from rising to a level that would open the A/C high pressure relief valve.
For additional information, refer to the appropriate Climate Control System - General Information article .
Scheme 185
Barometric (BARO) Pressure Sensor
The BARO pressure sensor is a variable capacitor sensor that processes a signal indicating atmospheric pressure. This allows the PCM to compensate for altitude. The PCM uses this information to calculate injection timing and glow plug control. At higher altitudes, glow plug on time is increased to reduce start-up smoke. The BARO sensor is located behind the instrument panel steering column cover.
Scheme 186
Boost Pressure Gauge
The boost pressure gauge is controlled by the instrument cluster. The PCM sends a message through the controller area network (CAN) to the instrument cluster indicating engine boost pressure.
Scheme 187
Brake Pedal Position (BPP) Switch
The BPP switch signals the PCM with a battery positive voltage (B+) signal whenever the brake pedal is applied.
The signal informs the PCM to disengage the torque converter clutch, speed control, and auxiliary idle control (if equipped).
If all the stoplamp bulbs are burned out (open), a high voltage is present at the PCM due to a pull-up resistor in the PCM. This provides fail-safe operation in the event the circuit to the BPP switch has failed.
Scheme 188
Brake Pressure Applied (BPA) Switch
Note. The BPA switch is present on vehicles equipped with speed control.
All vehicles have a single BPA switch. A BPA switch provides a backup for the BPP switch. Normally, a brakes-applied signal from the BPP switch disengages the speed control. If the BPP switch signal is lost, the BPA switch then supplies the brakes-applied signal to the speed control system. The BPA switch signal is also used in the transmission strategy and the key on engine running (KOER) self-test.
Scheme 189
Camshaft Position (CMP) Sensor
The CMP sensor is a variable reluctance sensor that responds to a rotating trigger protruding from the camshaft. The trigger is a single 9.525 mm (0.375 inches) diameter peg approximately 18 degrees wide, projecting 3-5 mm (0.12-0.20 inches) from the camshaft. The peg passes the sensor once per camshaft revolution and produces a single pulse. The camshaft speed is calculated from the frequency of the CMP sensor signal. The engine does not operate without a CMP signal.
Scheme 190
Cold Idle Kicker
The cold idle kicker strategy provides an increase in idle speed during cold engine warm up. During extended idle conditions, the PCM increases engine speed up to 1,100 RPM (normally 725 RPM for manual, 690 RPM for auto) to achieve a faster engine warm-up. The PCM uses the engine oil temperature (EOT) sensor and intake air temperature 2 (IAT2) inputs and adjusts the RPM accordingly, to a maximum of 1,100 RPM.
The idle speed is increased proportionately when the engine oil temperature is less than 70°C (158°F), the IAT2 is less than 20°C (68°F) and the engine has been at idle for more than 2 minutes. Applying the brake pedal, accelerator pedal, parking brake or clutch pedal (manual transmission) deactivates the cold idle kicker strategy and returns the idle speed to 690 RPM.
Allowing the engine to idle for more than 5 minutes with the EGR valve commanded closed, the variable geometry turbocharger duty cycle may step from 15% to 85%. This occurs momentary and repeats after a calibrated time. For additional information, refer to POWERTRAIN CONTROL SOFTWARE , VANE SWEEP .
Crankshaft Position (CKP) Sensor
The CKP signal source is a variable reluctance sensor mounted in the right front side of the engine block. The sensor reacts to a target wheel on the crankshaft. The target wheel is a 60 minus 2 tooth steel disk with 58 evenly spaced teeth and a SYNC gap (a minus 2 slot wide tooth). The sensor produces pulses for each tooth edge that passes it. The crankshaft speed is derived from the frequency of the CKP sensor signal. The crankshaft position is determined by synchronizing the SYNC tooth with the SYNC gap signals from the target wheel. Diagnostic information on the CKP input signal is obtained by carrying out accuracy checks on the frequency and duty cycle with software strategies. The PCM uses the CKP and CMP signals to calculate the engine speed and piston position. The CKP creates a signal used by the PCM to indicate cylinder identification in a particular bank. The CKP contains a permanent magnet that creates a magnetic field. The signal is created when the target wheel rotates and breaks the magnetic field created by the sensor. The engine will not operate without a CKP signal.
Scheme 191
Electronic Variable Geometry Turbocharger (VGT) Control Valve
The electronic VGT control valve is a 4-way proportional hydraulic flow control valve with a closed center position. The valve controls the linear actuator position of a closed loop hydraulic servo by charging and venting the flow on both sides of a piston. Linear displacement feedback from the actuator varies a feedback spring force to move the valve spool to the center closed position when the actuator reaches the desired position. Therefore, the actuator position is dependent only on the control valve current, it is independent of the hydraulic fluid temperature and viscosity.
Scheme 192
Engine Coolant Temperature (ECT) Sensor
The ECT sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the temperature increases, and resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature.
If the PCM receives a high engine temperature signal from the ECT, it adjusts fueling rates to protect the engine from damage due to overheating.
Scheme 193
Engine Oil Temperature (EOT) Sensor
The EOT sensor is a thermistor whose resistance decreases as engine oil temperature increases. The EOT signal is used by the PCM to calculate fuel quantity, injection timing, and glow plug operation.
At low ambient air temperatures and an oil temperature of less than 70°C (158°F), low idle is increased to maintain stable idle quality. Fuel quantity and timing is controlled throughout the total operating range to provide adequate torque and power.
An EOT signal detected out of range, high or low, by the PCM causes the PCM to substitute a temperature based on the ECT to be used for operating purposes.
Scheme 194
Exhaust Gas Recirculation (EGR) Actuator and Valve Position Sensor
The EGR actuator is a variable position valve that controls the amount of exhaust that enters the intake manifold. The EGR actuator is controlled by the PCM using a pulse width modulated (PWM) signal that varies from 0-100%. The EGR actuator consists of 2 components, a valve with an actuator, and a position sensor to monitor valve movement. The EGR valve position sensor is a potentiometer sensor which is needed to give the control circuit feedback to achieve the desired travel position. When the EGR receives a 5 volt reference signal and a ground from the PCM, a linear analog voltage signal from the sensor indicates the position of the EGR valve. Input signals from the manifold absolute pressure (MAP), exhaust pressure (EP), and barometric pressure (BARO) sensors are used by the PCM to calculate and control the EGR system flow.
Scheme 195
Exhaust Gas Recirculation (EGR) System Cooler
The exhaust gasses are directed through the EGR system cooler to remove heat before the gasses arrive at the EGR valve. Engine coolant is used to reduce the exhaust gas temperature by directing coolant flow through the EGR system cooler.
Scheme 196
Exhaust Pressure (EP) Sensor
The EP sensor is a variable capacitor sensor that is supplied a 5-volt reference signal by the PCM and returns a linear analog voltage signal that indicates pressure. The EP sensor measures the pressure in the LH exhaust manifold. The sensor feedback signal is used for VGT and EGR valve control.
An open or short in the EP sensor wiring results in an out-of-range low voltage at the PCM.
Scheme 197
Fan Speed Sensor (FSS)
The FSS is a Hall effect sensor integral to the visctronic drive fan (VDF). The PCM monitors the sensor input and controls the VDF speed based upon the engine coolant temperature, the transmission fluid temperature, and the intake air temperature (IAT) requirements. When an increase in fan speed for vehicle cooling is requested, the PCM monitors the FSS signal and outputs the required PWM signal to a fluid port valve within the VDF.
Glow Plug Indicator Lamp
The glow plug indicator lamp is located in the instrument cluster and is used to inform the operator when the engine is ready to be started. The indicator is controlled by the IC based on an electronic command signal from the PCM through the controller area network (CAN). The on-time normally varies between 1 and 10 seconds and is independent of the glow plug relay on-time. As a prove out, the indicator is commanded on at every ignition cycle even though the glow plug system may not be required.
Scheme 198
Injection Control Pressure (ICP) Sensor
The ICP sensor is a variable capacitor sensor that is supplied a 5-volt reference signal by the PCM and returns a linear analog voltage signal that indicates pressure. The primary function of the ICP sensor is to provide a feedback signal to indicate the rail pressure so that the PCM can command the correct injector timing, pulse width, and the correct injection control pressure for proper fuel delivery at all speed and load conditions. The ICP sensor along with the injection pressure regulator (IPR) form a closed loop fuel pressure control system.
If the PCM detects an inoperative ICP sensor, the PCM controls the injection control pressure from the estimated injection control pressure.
The ICP sensor bias varies between sensors. The amount of voltage the sensor deviates from a calculated reference value (sensor bias) may cause an injection control pressure calculation error.
Scheme 199
Injection Pressure Regulator (IPR)
The IPR is a PWM variable position valve that regulates the pressure in the ICP system. The IPR restricts the return flow path for oil from the high pressure pump. As the duty cycle increases, the IPR restriction to the drain increases, thus increasing the ICP. The IPR duty cycle is controlled by the PCM and is modulated from 0 to 65% depending upon the desired injection control pressure.
When the starter is engaged and the engine fails to start, the IPR command increases toward its maximum until the engine starts. The normal range for the IPR at idle is between 16-24%. An above 24% range indicates high effort or higher commanded ICP to achieve idle. A below 16% indicates low effort to achieve idle.
An open circuit results in minimal oil pressure and a no-start situation. A short to ground in a circuit results in maximum oil pressure, limited by a mechanical pop-off valve to 27,580 kPa (4,000 psi).
Scheme 200
Intake Air Temperature (IAT) Sensor
The IAT sensor is a thermistor device. The electrical resistance of a thermistor decreases as the temperature increases, and resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor providing a signal corresponding to temperature.
The IAT sensor is integrated into the MAF sensor.
Intake Air Temperature 2 (IAT2) Sensor
The IAT2 or manifold air temperature (MAT) sensor is a thermistor device. The electrical resistance of a thermistor decreases as the temperature increases, and resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor providing a signal corresponding to temperature.
The IAT2 sensor is located in the intake manifold. The sensor provides a manifold air temperature signal to the PCM. The PCM uses the IAT2 signal to control timing and fuel rate during cold starts and provide an input to the cold idle kicker
Scheme 201
Manifold Absolute Pressure (MAP) Sensor
The MAP sensor is a variable capacitor sensor that is supplied a 5-volt reference signal by the PCM and returns a voltage signal to the PCM relative to the intake manifold pressure. The sensor voltage increases as the pressure increases. The MAP sensor allows the PCM to determine the engine boost to calculate fuel quantity. In addition, the MAP signal is used to control smoke by limiting fuel quantity during acceleration until a specified boost pressure is obtained, and is used by the PCM for EGR system calculations and control. The MAP signal is also used to determine if an over boost condition is present.
A MAP signal concern detected by the PCM causes the PCM to calculate an estimated manifold pressure based on known engine conditions. If an over boost condition is detected, DTC P0234 is set and the engine performance is derated to protect the engine.
Scheme 202
Mass Air Flow (MAF) Sensor
The MAF sensor provides an analog voltage signal to the PCM proportional to the intake air mass. The MAF sensor uses a hot wire sensing element to measure the amount of air entering the engine. The hot wire is maintained at 200°C (392°F) above the ambient temperature. Air passing over the hot wire cools the wire. The current required to maintain the temperature of the hot wire is proportional to the air mass flow. The MAF signal is used to calculate the EGR flow rate and for concern detection.
The current PCM implementation contains a mass air flow interface, which consists of a 2-pole, differential input, low pass filter. This filter is designed to pass an analog signal, originating from the mass air sensor, while rejecting unwanted ignition noise, high frequency electrical interference, and ground offsets. The input to the interface is the analog voltage signal difference between MAF+ (mass air flow signal) and MAF- (mass air flow return). The MAF sensor output an analog voltage signal calibrated to 0.5 V at the lower limit of the flow range and 4.75 V at the upper limit of the flow range.
Scheme 203
Output Shaft Speed (OSS) Sensor
The OSS sensor detects the speed of the transmission output shaft. The sensor uses variations in a magnetic field caused by the OSS sensor gear to generate an output signal corresponding to shaft speed. The OSS sensor gear uses a repetitive pattern of 3 different angular displacements between the teeth. The magnetic sensor element may be a Hall effect sensor or magnetic pick-up. Due to the open collector design and the RC timing involved in the pull-up, the rising edge of the OSS sensor gear is not a reliable edge for critical timing, only the falling edge. The pull-up resistor is located in the PCM to provide a current for the sensor. This applies specifically to the automatic transmission.
Scheme 204
Parking Brake Switch
The parking brake switch signal indicates when the parking brake is applied. On all vehicles, the parking brake switch is located under the instrument panel. The parking brake switch deactivates the speed control if the brake is applied during speed control operation and provides a brake input for the cold idle kicker.
Passive Anti-Theft System (PATS)
The PATS prevents engine operation without the correctly encoded key. For additional information on the operation of this system, refer to the appropriate Anti-Theft - Passive Anti-Theft System (PATS) article .
Tachometer
The tachometer is controlled by the instrument cluster. The PCM sends an engine speed message through the CAN to the instrument cluster indicating the engine RPM.
Transmission Control (TC) Switch
The TC switch provides an input signal to the PCM whenever the switch is pressed. The overdrive cancel indicator illuminates when the TC switch is cycled to engage or disengage the overdrive function of the transmission. For additional information and diagnostics, refer to the appropriate Automatic Transaxle/Transmission article .
Scheme 205
Visctronic Drive Fan (VDF)
The VDF is an electrically actuated viscous clutch that consists of 3 main elements
- a working chamber
- a reservoir chamber
- an actuator (electromechanical valve and speed sensor)
The actuator valve controls the fluid flow from the reservoir into the working chamber. Once viscous fluid is in the working chamber, shearing of the fluid results in fan rotation. The valve is activated via a pulse width module (PWM) output signal from the PCM. By opening and closing the fluid port valve, the PCM controls the fan speed. Fan speed is measured through a Hall effect sensor, and is monitored by the PCM during closed loop operation. The PCM optimizes the fan speed based on the engine coolant temperature, the engine oil temperature, the transmission fluid temperature, the intake air temperature, or air conditioning requirements. When an increased demand for fan speed is requested for vehicle cooling, the PCM monitors the fan speed through the Hall effect sensor. If a fan speed increase is required, the PCM outputs the PWM signal to the fluid port, providing the required fan speed increase. During the key on, engine running (KOER) self-test, the PCM commands a 100% duty cycle. A diagnostic trouble code (DTC) is set if the PCM detects the voltage on the valve control circuit is not within the expected range or if the fan speed is less than a calibrated value.
Scheme 206
Water-in-Fuel Indicator
The water-in-fuel indicator is controlled by the instrument cluster (IC). The IC receives electronic information from the PCM through the CAN. If the water-in-fuel sensor indicates that there is water in the fuel separator/housing (located within the fuel conditioning module), the PCM sends a message to illuminate the water-in-fuel indicator.
Scheme 207
Overview
The powertrain control module (PCM) contains both engine and transmission microprocessors. Operating information, as well as concern information, is communicated between the 2 processors through the controller area network (CAN). Both can be programmed individually. However, a new PCM is installed as an assembly.
Fuel control is accomplished by the PCM and the fuel injector control module (FICM). The 2 modules communicate operational information through private J1939 CAN communications.
The EEC system provides optimum control of the engine and transmission through the enhanced capability of the PCM. The EEC system also has an on board diagnostics (OBD) monitoring system with features and functions to meet federal regulations on exhaust emissions.
The EEC system has 2 major divisions: hardware and software. The hardware includes the PCM, FICM, sensors, switches, actuators, solenoids, and interconnecting terminals. The software in the PCM provides the strategy control for outputs (engine and transmission hardware) based on the values of the inputs to the PCM. The software in the FICM provides the strategy control for the fuel injectors based on the values of the outputs from the PCM. The EEC hardware and software are discussed.
The PCM receives information from a variety of sensor and switch inputs. Based on the strategy and calibration stored within the memory chip, the PCM generates the appropriate output. The system is designed to minimize emissions and optimize fuel economy and driveability. The software strategy controls the basic operation of the engine and transmission, provides the OBD strategy, controls the malfunction indicator lamp (MIL), communicates to the scan tool through the data link connector (DLC), allows for flash electrically erasable programmable read only memory (EEPROM), and controls failure mode effects management (FMEM).
Modifications to OBD Vehicles
Modifications or additions to the vehicle may cause incorrect operation of the OBD system. Performance modifications that cause a Ford part to fail may not be covered by the Ford New Vehicle Limited Warranty. Burglar alarms, cellular telephones, and CB radios must be carefully installed. Do not install these devices by tapping into or running wires close to powertrain control system wires or components.
Scheme 208
Powertrain Control Module (PCM)
The center of the electronic engine control (EEC) system is the PCM. The PCM contains both engine and transmission microprocessors. Operating information, as well as concern information, is communicated between the 2 processors through controller area network (CAN) communications. Both can be programmed individually, however, a new PCM is installed as an assembly. The PCM has 3 electrical connectors (122 pins total). The PCM receives input from sensors and other electronic components (switches and relays) and places this information into random access memory (RAM) or keep alive memory (KAM). Based on information programmed into its read-only memory (ROM), the PCM generates output signals to control various relays, solenoids, and actuators.
The transmission control module (TCM) controls the power monitor strategy. The power monitor monitors the engine speed at idle. If an abnormal engine speed increase is detected, the power monitor commands the fuel injector control module (FICM) off in an effort to maintain a normal idle speed. Diagnostic trouble codes (DTCs) are stored if the power monitor is active.
Fuel Injector Control Module (FICM)
The FICM requires a 12-volt power source. The FICM receives power from the vehicle batteries through the FICM relay contacts each time the ignition is turned to the ON position. As the ignition is turned to the ON position, the FICM provides an internal ground to the coil side of the FICM relay. This closes the relay contacts and provides the FICM with the necessary power. The PCM communicates with the FICM using the CAN protocol. The CAN protocol is an international standards organization (ISO) standard for serial data communication. The CAN protocol standard includes a physical layer using differential transmission on a twisted pair of wires and a data link layer that defines different message types, arbitration rules for bus access, methods for concern detection and concern confinement. The FICM receives information from the PCM, including the volume of fuel desired, RPM, engine oil temperature, injection control pressure, and others. The FICM uses those signals to calculate fuel injection and duration. After calculating injector fuel delivery time, the FICM sends 48 volts at a 20-amp pulse to the correct injector so that the correct amount of fuel is delivered to the cylinder at the correct time.
The FICM has four high side driver outputs; two for the right bank and two for the left bank. The high side driver output function distributes energy to the correct bank based on a camshaft position output (CMPO) signal, and provides regulated current to the injectors. The PCM commands the fuel quantity and the FICM controls the duration and timing of the injection event. The FICM's low side driver outputs control the sequencing (firing order) of the engine.
Scheme 209
Glow Plug Control Module (GPCM)
Note. The wait-to-start indicator on-time is controlled by the PCM and is independent from the GPCM on-time.
The glow plug system consists of a solid state GPCM, glow plugs, and the associated wiring harness. The glow plug on-time is controlled by the PCM and is a function of oil temperature, barometric pressure, and battery voltage. The PCM enables the GPCM to power the individual glow plugs by providing direct battery voltage to the glow plugs. The GPCM monitors the individual glow plug operation. Concerns detected by the GPCM are transmitted to the PCM using a serial communication signal on a diagnostic line. Glow plug on-time normally varies between 1 to 120 seconds. In addition to PCM control, the GPCM internally limits the glow plug operation to 180 seconds regardless of the PCM commanded on-time. The power to the glow plugs is provided through the GPCM solid state drivers directly from the vehicle battery. The GPCM monitors and detects individual glow plug functionality and the control and communication links to the PCM.
Scheme 210
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 vehicle ignition is off so that this information is not lost.
Gold Plated Pins
Note. When installing new terminals make sure new gold plated terminals are used where gold plated terminals where originally used.
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 EEC components equipped with gold terminals vary by vehicle application.
Keep Alive Power (KAPWR)
The PCM stores the vehicle operating conditions in the KAM and uses this information to compensate for component variability. The KAPWR circuit supplies a constant battery voltage (B+) input to the PCM to maintain the memory contents when the ignition is in the OFF position.
Power Ground (PWRGND)
The PWRGND circuit(s) is directly connected to the battery negative terminal. PWRGND provides a return path for the PCM VPWR circuits.
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.
Signal Return (SIGRTN)
The SIGRTN circuit(s) is a dedicated return path for VREF applied components.
Vehicle Buffered Power (VBPWR)
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 PCM power relay and is controlled by the ignition switch. With the ignition in the START or RUN position, voltage is supplied to the PCM power relay coil. The supplied voltage energizes the relay and closes the internal relay contacts. With the relay contacts closed, VPWR is supplied to the PCM.
Computer Controlled Shutdown
The PCM controls the PCM power relay when the ignition is turned to the ON or START position, by grounding the PCM relay control (PCMRC) circuit. After the ignition is turned to the OFF, ACC or LOCK position, the PCM stays powered up until the correct engine shutdown occurs.
The ignition switch position run (ISP-R) circuit provides the ignition state input to the PCM. Based on the ISP-R signal the PCM determines when to power down the PCM power relay.
Diesel Engine Power Monitor (DEPM)
The DEPM strategy resides in the transmission control module (TCM) located inside of the powertrain control module (PCM). The function of the DEPM is to monitor the engine RPM when there is no power demand from the APP sensor.
Under normal engine idle operation, the DEPM value must always be higher than the engine RPM. In the event that the RPM does increase to its calibrated idle speed value following completion of deceleration fuel shutoff due to the injectors not turning off, the DEPM disables the crank and cam output signals sent by the PCM to the fuel injector control module (FICM). The fuel injector control module monitor (FICMM) input line informs the DEPM when the injectors are turned on and when the injectors are turned off. When the FICMM line is either shorted or open, the monitor strategy assumes that the fuel injectors are always turned on and sets a DTC.
Engine RPM Limiter
The PCM limits the engine RPM by cutting off fuel whenever the engine RPM limit is detected. The RPM limit is 4,000 RPM. The purpose of the engine RPM limiter is to prevent damage to the powertrain.
Flash Electrically Erasable Programmable Read Only Memory (EEPROM)
The flash EEPROM is an integrated circuit (IC) within the PCM and the FICM. This integrated circuit contains the software code required by the PCM to control the powertrain and by the FICM to control the fuel injectors. One feature of the flash EEPROM is that it can be electrically erased and then reprogrammed without removing the PCM or the FICM from the vehicle. If a software change is required to the PCM or the FICM, a new module is no longer necessary, the original module can be reprogrammed. The reprogramming is carried out through the data link connector (DLC).
Failure Mode Effects Management (FMEM)
The FMEM system is an alternate strategy in the PCM designed to maintain vehicle operation if one or more critical sensor inputs fail. When a sensor input is perceived to be out-of-limits by the PCM, an alternative strategy is initiated. The PCM substitutes a fixed value and continues to monitor the incorrect sensor input. If the suspect sensor operates within limits, the PCM returns to the normal engine running strategy. The FMEM operation results in continuous memory diagnostic trouble codes (DTCs) during normal engine operation and when carrying out the key on engine running (KOER) self-test mode.
High Speed Controller Area Network (CAN)
The high speed CAN is based on SAE J2284, ISO-11898, and is a serial communication language protocol used to transfer messages (signals) between electronic control modules or nodes. Two or more signals can be sent over one CAN circuit allowing 2 or more electronic modules or nodes to communicate with each other. This communication, or multiplexing, network operates at 500k/sec (kilobytes per second) and allows the electronic modules to share their information messages.
Included in these messages is diagnostic data sent over the CAN+ and CAN- lines to the DLC. The PCM connection to the DLC is typically done with a 2-wire, twisted pair cable used for network interconnection. The diagnostic data such as self-test or PIDs can be accessed with a scan tool. Information on scan tool equipment is described in DIAGNOSTIC METHODS .
Multiplexing
The increased number of modules on the vehicle dictate a more efficient method of communication. Multiplexing is the process of communicating several messages over the same signal path. This process allows multiple modules to communicate with each other through the signal path (CAN2+/CAN2-). Modules communicate with the PCM using CAN communications, to determine the priority in which the signals are sent. Refer to the HIGH SPEED CONTROLLER AREA NETWORK (CAN) for additional information.
Oil Cooler Performance Monitor
The software in the powertrain control module (PCM) provides the strategy control for the oil cooler performance monitor. The oil cooler monitor compares the engine coolant temperature to the engine oil temperature during normal engine operation. The oil cooler system maintains an acceptable engine oil temperature by transferring the heat generated in the engine oil to the engine cooling system.
The oil cooler monitor is enabled after the thermostat opens, the engine oil temperature is greater than the engine coolant temperature, and the engine speed is greater than a calibrated threshold. Once the enabling conditions are met, the oil cooler monitor calculates the difference between the engine oil temperature and engine coolant temperature and compares the readings to an expected threshold. The expected threshold is dependent on the vehicle speed and engine load conditions. If the temperature difference exceeds the maximum limit for greater than a specific amount of time, DTC P012F sets and the powertrain malfunction indicator (wrench) on the instrument cluster illuminates. This monitor runs continuously once the enabling conditions are met.
Powertrain Malfunction Indicator (Wrench)
The powertrain malfunction indicator (wrench) informs the driver that the PCM has detected a non OBD related component or system concern. When this occurs a DTC is set. The powertrain malfunction indicator (wrench) turns off through an ignition reset if the conditions are no longer met. The powertrain malfunction indicator (wrench) is located in the instrument cluster. The powertrain malfunction indicator (wrench) is illuminated by a PCM message sent through the controller area network (CAN) to the instrument cluster. To clear the DTCs, a command from the scan tool must be sent to the PCM.
For additional information, refer to the appropriate Instrumentation, Message Center, and Warning Chimes article, Instrument Panel Cluster (IPC) .
Vane Sweep
The PCM commands the variable geometry turbo actuator duty cycle from 15% to 85% in a step pattern to help the turbo vanes achieve full movement. Vane sweep occurs when the following conditions are present
- The vehicle is stopped.
- The EGR is commanded off.
- The engine speed is less than 1,160 RPM.
- The engine oil temperature is greater than a calibrated value.
Vane sweep repeats approximately every hour if the previous conditions still exist. Vane sweep may occur during scan tool commanded test functions.
Vehicle Speed Limiter
Note. Maximum speed may vary with load and axle ratio.
The vehicle is limited to a maximum speed of approximately 153 km/h (95 mph).
Malfunction Indicator Lamp (MIL)
The MIL informs the driver that the powertrain control module (PCM) has detected an OBD emission-related component or system concern. When this occurs on a California-calibrated engine, an OBD diagnostic trouble code (DTC) is set. On a federal calibrated engine and transmission, certain concerns also illuminate the MIL.
- The MIL is located in the instrument cluster.
- The indicator is illuminated by a PCM message sent through the controller area network (CAN) to the instrument cluster.
- An engine or transmission with federal calibration operating in the failure mode effects management (FMEM) may cause the MIL to be illuminated.
- To turn off the MIL after a repair, a clear DTCs command from the scan tool must be sent to the PCM.
- For any MIL concern, go to «QUICK TEST»(/ford/cutaway-e350-super-duty/2008-2012/remont/testing-diagnostics/#engine-controls-diagnostic-methods-e-350-60l-diesel-models__quick-test) .
Scheme 211
Catalytic Converter
All vehicles are equipped with a catalytic converter.
Electro-Hydraulic Injector
The electro-hydraulic injector is composed of 3 major components: The oil control, the pressure amplification, and the nozzle assembly. The injector uses 2, 48-volt at 20-amp coils to control a spool valve that directs oil flow in and out of the injector. The fuel injector has a self-extracting hold-down clamp.
Scheme 212
| Item | Description |
|---|---|
| 1 | Closing coil |
| 2 | Control valve body |
| 3 | Amplifier piston (7:1 ratio) |
| 4 | Piston return spring |
| 5 | Plunger |
| 6 | Valve opening pressure spring, 260 bar (3,770 psi) |
| 7 | Nozzle valve |
| 8 | Opening coil |
| 9 | Spool valve (control valve) |
| 10 | Case nut |
| 11 | Fuel strainer (3) |
| 12 | Nozzle assembly |
ITEM DESCRIPTION CHART
Electro-Hydraulic Injector Amplifier Piston
The high pressure oil flows from the oil rails into an electro-hydraulic injector amplifier piston located in the injector. Oil entry and exit to and from the amplifier piston is controlled by a coil-operated spool valve.
Electro-Hydraulic Injector Fuel Plunger
The electro-hydraulic injector fuel plunger is located in the injector and is driven by the amplifier piston. The fuel plunger injects fuel into the combustion chamber at pressures of up to 196,500 kPa (28,500 psi) through the nozzle assembly. Fuel is supplied to the injector at approximately 345 kPa (50 psi) through fuel rails in the cylinder heads.
Engine Timing
The powertrain control module (PCM) commands the fuel quantity. The fuel injector control module (FICM) controls the duration of the injection event and is shown as parameter identification (PID) FUELPW on the scan tool.
The PCM controls the injection pressure and fuel volume by varying the injection oil pressure with the injection pressure regulator (IPR). The command to the IPR is a 12-volt, pulse width modulated (PWM) signal controlled on the ground side.
The injection oil pressure command is shown as PID IPR which is the percentage ON of the PWM signal. The injection oil pressure is shown as PID ICP.
The PCM uses camshaft position (CMP) and crankshaft position (CKP) input signals to calculate the engine speed and position. The PCM conditions both input signals and supplies the FICM with the CMP and CKP output signals. The FICM uses the CMP and CKP output signals to determine the correct sequence for injector firing. The PCM sends information about the fuel demand, engine oil temperature (EOT), and injection control pressure (ICP) through the CAN to the FICM. The FICM uses this information to calculate the injection cycle.
Fueling Corrections
The PCM adjusts the injector output based on the oil temperature information received from the EOT sensor and turbo boost information received from the manifold absolute pressure (MAP) sensor and the barometric pressure (BARO) sensor. These corrections are necessary to meet emissions requirements and to optimize power. The engine coolant temperature (ECT) and the EOT sensors are used as the primary input to the PCM to enable adaptive cooling. This provides a means of providing adequate cooling in severe engine temperature conditions. When the engine coolant temperature is greater than 105°C (221°F) or the engine operating temperature is greater than 123°C (253°F), the fueling rate of the engine is modified to provide cooling protection and prevent engine damage due to overheating. Outputs of these sensors can be monitored using a scan tool reading PIDs.
The coil-operated spool valve requires 48 volts at up to 20 amps to operate, which is more power than the PCM can supply. Therefore, a high power device, the FICM, is used to supply power to the solenoid on command from the PCM. For additional information refer to the Diesel POWERTRAIN CONTROL HARDWARE .
Fuel System
Fuel is drawn from the fuel tank through the primary filter (located in the fuel conditioning module) by the electric fuel pump. Pressurized fuel, approximately 310-379 kPa (45-55 psi), is supplied to the secondary filter (the fuel filter housing located on the front left side of the engine) by means of the electric pump and regulator valve. The regulator relieves the pressure, sending fuel back to the fuel tank. Only the filtered fuel going through the fuel filter goes to the heads. A check valve is located on both heads to prevent fuel pressure spikes in the fuel rail.
Scheme 213
| Item | Description |
|---|---|
| 1 | Electric fuel pump |
| 2 | Fuel inlet |
| 3 | Fuel filter housing |
| 4 | Fuel filter (secondary) |
| 5 | Regulator |
| 6 | Fuel return line |
| 7 | Check valves |
| 8 | Right head |
| 9 | Left head |
| 10 | Restriction check |
| 11 | Fuel pump pressure check |
| 12 | Fuel filter (primary) |
ITEM DESCRIPTION CHART
High Pressure Oil System
The fuel injectors are powered by lubricating oil which is pressurized by a high pressure pump in the engine valley. The pump output pressure ranges from 3,102 to 27,579 kPa (450 psi to 4,000 psi). Oil pressure is controlled by the PCM through the injection pressure regulator (IPR) valve. The PCM controls pressure in the oil rail by opening (relieving pressure) and closing (increasing pressure) the IPR valve. The high pressure oil is delivered to the oil rails in the cylinder heads. An injection control pressure (ICP) sensor mounted on the high pressure pump cover sends an analog voltage signal (0.5 to 5.0 volts) to the PCM for feedback control of the oil pressure.
Scheme 214
| Item | Number | Description |
|---|---|---|
| 1 | 6608 | Oil pump |
| 2 | 6A638 | Oil cooler |
| 3 | 6714 | Oil filter |
| 4 | High pressure reservoir (part of 6010) | |
| 5 | 9A543 | High pressure oil pump |
| 6 | 9F838 | ICP sensor |
| 7 | 9C968 | IPR valve |
| 8 | Drain to crankcase (part of 6010) | |
| 9 | 9D280 | High pressure oil rails |
| 10 | 9E527 | Fuel injectors |
ITEM DESCRIPTION CHART
Scheme 215
Scheme 216
Scheme 217
The California Air Resources Board (CARB) began regulation of OBD for diesel vehicles sold in California beginning with the 1997 model year. OBD requires monitoring of emission-related components. The malfunction indicator lamp (MIL) is required to light and alert the driver of a concern and the need for repair of the emission control system. A diagnostic trouble code (DTC) is associated with the MIL identifying the specific area of the concern.
Note. The OBD system is used on vehicles under 6,350 kg (14,000 lb) gross vehicle weight rating (GVWR). The engine manufacturer diagnostics (EMD) system is used on vehicles over 6,350 kg (14,000 lb) GVWR.
The OBD system meets government regulations by monitoring the emission control system. When a system or component exceeds emission thresholds or a component operates outside of tolerance, a DTC is stored and the MIL is illuminated.
The OBD monitors detect system concerns and initiate DTC setting and MIL activation. Concern detection strategy and MIL operation are associated with drive cycles. An OBD pending DTC is stored in the powertrain control module (PCM) keep alive memory (KAM) when a concern is first detected. The MIL is turned on after 2 consecutive drive cycles with concerns. The DTC is cleared after 40 engine warm-up cycles without the concern being detected once the MIL is turned off. Once a monitor turns on the MIL, it requires 3 consecutive drive cycles without a concern for the MIL to turn off. The operation of each of the OBD monitors is discussed in detail within this article.
The OBD computer program in the PCM coordinates the OBD self-monitoring system. This program controls all the monitors and interactions, DTC and MIL operation, freeze frame data, and scan tool interface.
Freeze frame data describes stored engine conditions such as the state of the engine RPM and load at the point the first concern is detected. This data is accessible with the scan tool to assist in repairing the vehicle.
OBD inspection maintenance (IM) readiness DTC P1000 indicates that not all of the OBD monitors have been completed since the PCM KAM was last cleared. In some states, it may not be possible to obtain vehicle registration if DTC P1000 is detected during inspection. To erase DTC P1000 from the PCM, operate the vehicle until the DTC is cleared using the manufacturer's specified drive cycle.
The OBD system is comprised of the comprehensive component monitor (CCM), the glow plug monitor, the misfire detection monitor, and the exhaust gas recirculation (EGR) monitor.
Starting with the 2007 model year, vehicles not required to comply with current OBD requirements use an EMD system. EMD systems are used on all California and Federal gas and diesel on-road heavy duty engines used in vehicles over 6,350 kg (14,000 lb) GVWR. EMD systems are required to functionally monitor the fuel delivery system, EGR system, particulate matter trap, as well as emission related PCM inputs for circuit continuity and rationality, and emission related outputs for circuit continuity and functionality. EMD requirements are very similar to previous OBD system requirements. As such, previous OBD system principles are employed, with the addition of some CCM rationality and functionality checks. EMD vehicles use the same PCM, controller area network (CAN), data link connector (DLC) and PCM software as the corresponding OBD vehicles.
Deviations From Standard Gasoline Implementation of OBD
- Readiness (all monitors complete) is based on diagnostics for the following diesel engine systems: CCM misfire detection monitor EGR monitor The glow plug monitor is part of the CCM. Readiness is based on every OBD (component) having run sufficiently to have found a concern without regard to whether or not a concern exists.
- To clear the DTC P1000, carry out the drive cycle. For additional information, refer to «DRIVE CYCLES»(/ford/cutaway-e350-super-duty/2008-2012/remont/testing-diagnostics/#engine-controls-diagnostic-methods-e-350-60l-diesel-models) .
- The command to clear DTCs only clears DTC P1000 if all drive cycle testing has been satisfied. All other detected DTCs are cleared with a CLEAR code command from the scan tool if the concern that caused the DTC is no longer present.
Comprehensive Component Monitor (CCM)
The CCM is an on board strategy designed to monitor a concern in any electronic component or circuit that provides an input or output signal to the powertrain control module (PCM) and is not exclusively monitored by another monitor system. Inputs and outputs are considered inoperative when a concern exists due to a lack of circuit continuity, out-of-range value, or a failed rationality check.
The CCM covers many components and the related circuits. The tests vary depending on the hardware, function, and type of signal. For example, analog inputs are typically checked for opens, shorts, out-of-range values, and rationality. This type of monitoring is carried out continuously. These tests may require the monitoring of several components and may only be carried out under the appropriate test conditions. Some outputs are also monitored for the correct function by observing the reaction of the control system to a given change in the output command. An example of this is the injection control system.
In general, the CCM covers a broad range of individual component and circuit checks, and testing is carried out under various conditions. The CCM is enabled after the ignition switch is turned on for 3 seconds and the malfunction indicator lamp (MIL) is activated if the concern detected affects emissions. All of the CCM tests are also carried out during the on-demand self-test.
The following is an example of some of the input and output components monitored by the CCM. The components monitored may belong to the engine, transmission, or any other PCM supported subsystem.
Scheme 218
- The input components monitored include the engine oil temperature (EOT), accelerator pedal position (APP), and camshaft position (CMP).
- The output components monitored include the injection pressure regulator (IPR) and exhaust gas recirculation (EGR) valve.
- The MIL is activated after a concern is detected if the concern detected affects emissions.
Glow Plug Monitor
The engine uses a glow plug monitor system designed to detect failed glow plugs or failed wiring in the glow plug system. DTCs indicate which cylinder has failed glow plugs or failed glow plug wiring.
Scheme 219
The key on engine off (KOEO) test is carried out in order to test the glow plug control module (GPCM) control circuit for failure. The glow plugs are not operated during this test.
The glow plug monitor self-test is a functional KOER test of the PCM carried out on demand with the engine running and the A/C off. The PCM activates the GPCM which monitors the glow plugs. The accelerator pedal may be used to increase the engine speed to increase voltage if needed. A concern must be present at the time of testing for the test to detect a concern. The DTCs are sent to the PCM on the diagnostic line and output to the scan tool.
The following is an example of some of the input and output components monitored by the PCM. The components monitored belong to the engine system.
- The input components monitored by the PCM are the engine oil temperature (EOT) and the barometric pressure (BARO) sensor.
- The output component monitored by the PCM is the GPCM.
- The MIL is activated after a concern if the concern detected affects emissions.
Misfire Detection Monitor
The misfire detection monitor is an on board strategy designed to monitor engine misfire and identify the specific cylinder in which the misfire occurred. Misfire is detected using the crankshaft position (CKP) and camshaft position (CMP) sensors. To determine if a misfire has occurred the powertrain control module (PCM) monitors deceleration of the crankshaft and compares the information received to engine speed and engine load. If a misfire event is determined, the PCM uses the CKP and the CMP sensor signal information to determine which cylinder misfired.
The misfire event is defined as poor compression, fuel delivery, or mechanical engine failure. The misfire detection monitor is enabled only when certain base engine conditions are first satisfied. Input from the engine oil temperature (EOT), CKP, mass fuel desired (MFDES), exhaust pressure (EP), intake air temperature (IAT), fuel level input (FLI) and injector control pressure (ICP) sensors is required to enable the monitor.
- The CKP signal generated is the main input used in determining cylinder misfire.
- The input signal generated by the CKP sensor is derived by sensing the passage of the teeth from the crankshaft position wheel, which is mounted on the crankshaft.
- The input signal to the PCM is used to calculate the time between CKP edges and also crankshaft rotational velocity and acceleration. By comparing the accelerations of each cylinder event, the power loss of each cylinder is determined. When the power loss of a particular cylinder is sufficiently less than a calibrated value, and other criteria is met, the suspect cylinder is determined to have misfired.
Misfire Type B
Upon detection of a misfire type B (1,000 revolutions), which exceeds the emissions threshold or causes a vehicle to fail an inspection and maintenance tailpipe emissions test, the MIL illuminates and a DTC is stored.
The DTC associated with multiple cylinder misfire is DTC P0300.
The DTCs associated with cylinder misfire are P0301, P0302, P0303, P0304, P0305, P0306, P0307, and P0308.
| DTC | Description | Possible Causes | Diagnostic Aides |
|---|---|---|---|
| P0300 Random Misfire | The random misfire DTC indicates multiple cylinders are misfiring or the PCM cannot identify which cylinder is misfiring. | Fuel concern Oil aeration High pressure oil pump concern Base engine Fuel injectors | |
| P0301 - P0308 Misfire Detection Monitor | The misfire detection monitor is designed to monitor engine misfire and identify the specific cylinder effected due to poor compression or any other cause. | Base engine Injector | If the MIL is on steady state due to a misfire, this indicates the threshold for emissions was exceeded. |
DIAGNOSTIC TROUBLE CODES CHART