Ford training section1 description and operation

SECTION Description and Operation Contents Vehicle Emission Control Information (VECI) 1-1 Vehicle Certification Label .1-5 Base Engine Calibration Information 1-5 Vehicle Emission Control Information (VECI) Acronym Definitions 1-8 Engine Control Components 1-10 Accelerator Pedal Position (APP) Sensor 1-10 Ambient Air Temperature (AAT) Sensor 1-11 Barometric Pressure (BARO) Sensor 1-12 Brake Pedal Position (BPP) Switch 1-12 Brake Pressure Switch .1-13 Camshaft Position (CMP) Sensor 1-13 Canister Vent (CV) Solenoid 1-14 Charge Air Cooler Temperature (CACT) Sensor .1-15 Check Fuel Cap Indicator 1-15 Clutch Pedal Position (CPP) Switch 1-15 Coil On Plug (COP) 1-16 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Coil Pack 1-16 Crankshaft Position (CKP) Sensor 1-18 Cylinder Head Temperature (CHT) Sensor .1-19 Differential Pressure Feedback Exhaust Gas Recirculation (EGR) Sensor .1-19 Electric Cooling Fan 1-21 Electric Exhaust Gas Recirculation (EEGR) Valve 1-22 Electronic Throttle Actuator Control (TAC) 1-23 Electronic Throttle Body Throttle Position Sensor (ETBTPS) 1-24 Engine Coolant Temperature (ECT) Sensor 1-24 Engine Oil Temperature (EOT) Sensor 1-24 Evaporative Emission (EVAP) Canister Purge Valve 1-25 Evaporative Emission (EVAP) Canister Purge Check Valve 1-26 Evaporative Emission (EVAP) Natural Vacuum Leak Detection (NVLD) Module .1-27 Exhaust Gas Recirculation (EGR) Orifice Tube Assembly 1-28 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Exhaust Gas Recirculation (EGR) System Module (ESM) 1-28 Exhaust Gas Recirculation (EGR) Vacuum Regulator Solenoid 1-29 Exhaust Gas Recirculation (EGR) Valve 1-30 Fan Control 1-31 Fan Speed Sensor (FSS) 1-33 Fuel Injection Pump 1-33 Fuel Injectors 1-35 Fuel Injectors — Direct Injection 1-35 Fuel Pump (FP) Module .1-36 Fuel Pump (FP) Module and Reservoir .1-38 Fuel Rail Pressure (FRP) Sensor 1-38 Fuel Rail Pressure Temperature (FRPT) Sensor 1-38 Fuel Tank Pressure (FTP) Sensor .1-39 Heated Oxygen Sensor (HO2S) .1-40 Idle Air Control (IAC) Valve 1-41 Inertia Fuel Shut-off (IFS) Switch .1-42 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Intake Air Temperature (IAT) Sensor .1-42 Intake Manifold Tuning Valve (IMTV) .1-44 Knock Sensor (KS) 1-45 Manifold Absolute Pressure (MAP) Sensor .1-45 Mass Air Flow (MAF) Sensor .1-46 Output Shaft Speed (OSS) Sensor 1-48 Power Steering Pressure (PSP) Sensor 1-48 Power Steering Pressure (PSP) Switch 1-49 Power Take-Off (PTO) Switch and Circuits .1-49 Throttle Position (TP) Sensor 1-50 Transmission Control Indicator Lamp (TCIL) .1-50 Transmission Control Switch (TCS) 1-50 Turbocharger 1-51 Turbocharger Boost Pressure (TCBP) Sensor 1-52 Turbocharger Bypass (TCBY) Valve 1-52 Turbocharger (TC) Wastegate Regulating Solenoid Valve 1-53 Universal Heated Oxygen Sensor (HO2S) 1-53 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Vehicle Speed Sensor (VSS) .1-54 Engine Control (EC) System 1-55 Powertrain Control Hardware .1-57 Powertrain Control Module (PCM) .1-57 PCM Locations 1-57 Fuel Pump Control Module 1-61 Fuel Pump Driver Module (FPDM) 1-62 Keep Alive Memory (KAM) .1-62 Power and Ground Signals 1-62 Powertrain Control Module - Vehicle Speed Output (PCM-VSO) .1-64 Powertrain Control Software 1-66 Adaptive Airflow 1-66 Check Fuel Cap Indicator 1-66 Computer Controlled Shutdown 1-66 Deceleration Fuel Shut-Off (DFSO) 1-66 Engine Fluid Temperature Management 1-66 Engine RPM And Vehicle Speed Limiter 1-67 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Fail-Safe Cooling Strategy 1-67 Failure Mode Effects Management (FMEM) 1-68 Flash Electrically Erasable Programmable Read Only Memory (EEPROM) 1-68 Fuel Level Input (FLI) 1-68 Fuel Trim 1-68 High Speed Controller Area Network (CAN) .1-69 Idle Air Trim 1-69 Idle Speed Control Closed Throttle Determination — Applications Without Electronic Throttle Control (ETC) 1-70 International Standards Organization (ISO) 14229 Diagnostic Trouble Code (DTC) Descriptions 1-70 Multiplexing 1-74 Multiplexing Implementation .1-74 Permanent Diagnostic Trouble Code (DTC) 1-75 Malfunction Indicator Lamp (MIL) 1-76 Catalyst and Exhaust Systems 1-77 Evaporative Emission (EVAP) Systems 1-82 Exhaust Gas Recirculation (EGR) Systems 1-85 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Differential Pressure Feedback Exhaust Gas Recirculation (EGR) System 1-85 Electric Exhaust Gas Recirculation (EEGR) System 1-86 Exhaust Gas Recirculation (EGR) System Module (ESM) 1-87 Fuel Systems 1-90 Electronic Returnless Fuel System (ERFS) .1-90 Fuel Pump Control — ERFS 1-92 Fuel Pump Monitor (FPM) — ERFS 1-94 Mechanical Returnless Fuel System (MRFS) — Single Speed 1-95 Fuel Pump Control — Single Speed MRFS 1-96 Fuel Pump Monitor (FPM) — Single Speed MRFS 1-97 Mechanical Returnless Fuel System (MRFS) — Dual Speed 1-97 Fuel Pump Control — Dual Speed MRFS .1-99 Fuel Pump Monitor (FPM) — Dual Speed MRFS .1-99 High Pressure Fuel System 1-101 Ignition Systems 1-103 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Intake Air Systems .1-107 Positive Crankcase Ventilation (PCV) System 1-115 Supercharger and Charge Air Cooler (CAC) Systems 1-118 Torque Based Electronic Throttle Control (ETC) 1-122 Turbocharger and Charge Air Cooler (CAC) Systems 1-128 Variable Camshaft Timing (VCT) System 1-132 On Board Diagnostics (OBD) Monitors 1-135 OBD I, OBD II and Engine Manufacturer Diagnostics (EMD) Overview .1-135 Air Fuel Ratio Imbalance Monitor 1-139 Catalyst Efficiency Monitor 1-140 General Catalyst Monitor Operation .1-142 Integrated Air Fuel Catalyst Monitor 1-143 Cold Start Emission Reduction Monitor .1-144 Comprehensive Component Monitor (CCM) .1-148 Electric Exhaust Gas Recirculation (EEGR) System Monitor .1-150 Enhanced Thermostat Monitor 1-153 2011Powertrain Control/Emissions Diagnosis, 8/2010 SECTION Description and Operation Contents (Continued) Evaporative Emission (EVAP) Leak Check Monitor 1-154 Engine On EVAP Leak Check Monitor — Fiesta 1-154 Engine On EVAP Leak Check Monitor — All Others 1-155 Engine Off Natural Vacuum (EONV) EVAP Leak Check Monitor 1-157 Natural Vacuum Leak Detection (NVLD) Small Leak Monitor 1-160 Exhaust Gas Recirculation (EGR) System Monitor — Differential Pressure Feedback EGR and EGR System Module (ESM) 1-162 Fuel System Monitor 1-164 Heated Oxygen Sensor (HO2S) Monitor .1-166 Misfire Detection Monitor .1-168 Positive Crankcase Ventilation (PCV) System Monitor .1-174 Thermostat Monitor 1-175 Variable Camshaft Timing (VCT) Monitor 1-177 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-1 Table of Contents Vehicle Emission Control Information (VECI) VECI Decal Each vehicle has a VECI decal containing emission control information that applies specifically to the vehicle and engine The specifications on the decal are critical to repairing the emissions systems Typical VECI Decal VECI Decal Location The decal is typically located on the underside of the hood or on the radiator support sight shield Engine/Evaporative Emission (EVAP) System Information Manufacturers must use a standardized system for identifying their individual engine families The system described below was developed by the Environmental Protection Agency (EPA) in 1991 to meet new regulatory requirements for 1994 and later model years The engine family group and evaporative family name consist of 12 characters each Both the engine family group and the evaporative family name are listed in the box on the emission decal in the area marked as engine evaporative family information The first line contains engine size and the 12-character engine family group The second line contains the 12-character evaporative family name information Both the engine family group and the evaporative family name are specific to the vehicle Refer to the Engine Family Group and the Evaporative Family Name worksheet for decoding information 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-163 Exhaust Gas Recirculation (EGR) System Monitor — Differential Pressure Feedback EGR and EGR System Module (ESM) EGR System Monitor - Differential Pressure Feedback EGR 2011Powertrain Control/Emissions Diagnosis, 8/2010 1-164 Description and Operation Fuel System Monitor The fuel system monitor is an on board strategy designed to monitor the fuel control system The fuel control system uses fuel trim tables stored in the powertrain control module (PCM) keep alive memory (KAM) to compensate for the variability that occurs in fuel system components due to normal wear and aging Fuel trim tables are based on air mass During closed-loop fuel control, the fuel trim strategy learns the corrections needed to correct a biased rich or lean fuel system The correction is stored in the fuel trim tables The fuel trim has means of adapting: long term fuel trim and a short term fuel trim Refer to Powertrain Control Software, Fuel Trim in this section Long term fuel trim relies on the fuel trim tables and short term fuel trim refers to the desired air/fuel ratio parameter called LAMBSE LAMBSE is calculated by the PCM from the heated oxygen sensor (HO2S) inputs and helps maintain a 14.7:1 air/fuel ratio during closed-loop operation Short term fuel trim and long term fuel trim work together If the HO2S indicates the engine is running rich, the PCM corrects the rich condition by moving the short term fuel trim into the negative range, less fuel to correct for a rich combustion If after a certain amount of time the short term fuel trim is still compensating for a rich condition, the PCM learns this and moves the long term fuel trim into the negative range to compensate and allow the short term fuel trim to return to a value near 0% Inputs from the engine coolant temperature (ECT) or cylinder head temperature (CHT), intake air temperature (IAT), and mass air flow (MAF) sensors are required to activate the fuel trim system, which in turn activates the fuel system monitor Once activated, the fuel system monitor looks for the fuel trim tables to reach the adaptive clip (adaptive limit) and LAMBSE to exceed a calibrated limit The fuel system monitor stores the appropriate DTC when a concern is detected as described below The HO2S detects the presence of oxygen in the exhaust and provides the PCM with feedback indicating air/fuel ratio A correction factor is added to the fuel injector pulse width calculation and the mass air flow calculation, according to the long and short term fuel trims as needed to compensate for variations in the fuel system When deviation in the LAMBSE parameter increases, air/fuel control suffers and emissions increase When LAMBSE exceeds a calibrated limit and the fuel trim table has clipped, the fuel system monitor sets a DTC as follows: The DTCs associated with the monitor detecting a lean shift in fuel system operation are P0171 (Bank 1) and P0174 (Bank 2) The DTCs associated with the monitor detecting a rich shift in fuel system operation are P0172 (Bank 1) and P0175 (Bank 2) The malfunction indicator lamp (MIL) is activated after a concern is detected on consecutive drive cycles Typical fuel system monitor entry conditions: • RPM range greater than idle • Air mass range greater than 5.67 g/sec (0.75 lb/min) • Purge duty cycle of 0% 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-165 Fuel System Monitor Typical fuel monitor thresholds: • Lean Condition Concern: LONGFT greater than 25%, SHRTFT greater than 5% • Rich Condition Concern: LONGFT less than 25%, SHRTFT less than 10% Fuel System Monitor 2011Powertrain Control/Emissions Diagnosis, 8/2010 1-166 Description and Operation Heated Oxygen Sensor (HO2S) Monitor The HO2S monitor is an on board strategy designed to monitor the HO2Ss for concerns or deterioration which can affect emissions The fuel control or stream HO2S are checked for correct output voltage and response rate Response rate is the time it takes to switch from lean to rich or rich to lean The rear or stream HO2S is monitored for correct output voltage and is used for catalyst monitoring and fore-aft oxygen sensor (FAOS) control Input is required from the camshaft position (CMP), crankshaft position (CKP), engine coolant temperature (ECT) or cylinder head temperature (CHT), fuel rail pressure temperature (FRPT), fuel tank pressure (FTP), intake air temperature (IAT), mass air flow (MAF), manifold absolute pressure (MAP), and throttle position (TP) sensors and the vehicle speed sensor (VSS) to activate the HO2S monitor The fuel system monitor and misfire detection monitor must also have completed successfully before the HO2S monitor is enabled For applications using a universal HO2S in the upstream or stream position, there are additional DTCs such as heater temperature control, additional circuit diagnostics, lack of movement, and fore-aft oxygen sensor catalyst optimization The HO2S senses the oxygen content in the exhaust flow The typical HO2S outputs a voltage between and 1.0 volt Lean of stoichiometric, air/fuel ratio of approximately 14.7:1, the HO2S generates a voltage between and 0.45 volt Rich of stoichiometric, the HO2S generates a voltage between 0.45 and 1.0 volt The current required to maintain the universal HO2S at 0.45 volt is used by the powertrain control module (PCM) to calculate the air/fuel ratio The HO2S monitor evaluates the HO2Ss for correct function The time between HO2S switches is monitored after vehicle startup and during closed loop fuel conditions Excessive time between switches or no switches since startup indicates a concern Since lack of switching concerns can be caused by HO2S concerns or by shifts in the fuel system, diagnostic trouble codes (DTCs) are stored that provide additional information for the lack of switching concern Different DTCs indicate whether the sensor always indicates lean, rich, or disconnected The HO2S signal is also monitored for high voltage, in excess of 1.1 volts An over-voltage condition is caused by a HO2S heater or battery power short to the HO2S signal line A functional test of the rear HO2Ss is done during normal vehicle operation The peak rich and lean voltages are continuously monitored Voltages that exceed the calibrated rich and lean thresholds indicate a functional sensor If the voltages have not exceeded the thresholds after a long period of vehicle operation, the air/fuel ratio may be forced rich or lean in an attempt to get the rear sensor to switch This situation normally occurs only with a green, less than 804.7 km (500 mi), catalyst If the sensor does not exceed the rich and lean peak thresholds, a concern is indicated Also, a deceleration fuel shut off rear HO2S response test is done during a deceleration fuel shut-off (DFSO) event Carrying out the HO2S response test during a DFSO event helps to isolate a sensor concern from a catalyst concern The response test monitors how quickly the sensor switches from a rich to lean voltage It also monitors if there is a delay in the response to the rich or lean condition If the sensor responds very slowly to the rich to lean voltage switch or is never greater than a rich voltage threshold or less than a lean voltage threshold, a concern is indicated The malfunction indicator lamp (MIL) is activated after a concern is detected on consecutive drive cycles 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-167 Heated Oxygen Sensor (HO2S) Monitor HO2S Monitor 2011Powertrain Control/Emissions Diagnosis, 8/2010 1-168 Description and Operation 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 has occurred Misfire is defined as lack of combustion in a cylinder due to absence of spark, poor fuel metering, poor compression, or any other cause The misfire detection monitor is enabled only when certain base engine conditions are first satisfied Input from the engine coolant temperature (ECT) or cylinder head temperature (CHT), intake air temperature (IAT), and mass air flow (MAF) sensors is required to enable the monitor The misfire detection monitor is also carried out during an on-demand self-test The powertrain control module (PCM) synchronized ignition spark is based on information received from the crankshaft position (CKP) sensor The CKP sensor signal generated is also the main input used in determining cylinder misfire The input signal generated by the CKP sensor is derived by sensing the passage of teeth from the crankshaft position wheel mounted on the end of the crankshaft The input signal to the PCM is then used to calculate the time between CKP sensor signal edges and the 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 are met, then the suspect cylinder is determined to have misfired The malfunction indicator lamp (MIL) is activated after one of the above tests fail on consecutive drive cycles Misfire Detection Monitor 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-169 Misfire Detection Monitor Misfire Monitor Operation A low data rate (LDR) and high data rate (HDR) are the different types of misfire monitoring systems used The LDR system is capable of meeting the federal test procedure monitoring requirements on most engines and is capable of meeting the full-range of misfire monitoring requirements on 4-cylinder engines The HDR system is capable of meeting the full-range of misfire monitoring requirements on 6-cylinder and 8-cylinder engines The HDR system on these engines meets the full-range of misfire phase-in requirements specified in the OBD regulations The PCM software allows for detection of any misfires that occur engine revolutions after initially cranking the engine This meets the OBD requirement to identify misfires within engine revolutions after exceeding the warm drive, idle RPM Low Data Rate (LDR) System The LDR misfire monitor uses a low data rate CKP sensor signal which indicates one position reference at 10 degrees before top dead center (BTDC) for each cylinder event The PCM uses the CKP sensor signal to calculate the crankshaft speed and acceleration for each cylinder The crankshaft acceleration is then processed to detect a sporadic, single-cylinder misfire patterns or multi-cylinder misfire patterns The changes in overall engine RPM are removed by subtracting the median engine acceleration over a complete engine cycle The resulting deviant cylinder acceleration values are used in evaluating misfire Refer to the Generic Misfire Processing in this section for more information High Data Rate (HDR) System The HDR misfire monitor uses a high data rate CKP sensor signal which indicates 18 position references per crankshaft revolution This high resolution signal is processed using different algorithms The first algorithm is optimized to detect hard misfires on one or more continuously misfiring cylinders The low pass filter filters the high-resolution crankshaft velocity signal to remove some of the crankshaft torsional vibrations that degrade signal to noise Two low pass filters are used to enhance detection capability: a base filter and a more aggressive filter to enhance single-cylinder capability at higher RPM This significantly improves detection capability for continuous misfires on single cylinders up to red line The second algorithm, called pattern cancellation, is optimized to detect low rates of misfire The algorithm learns the normal pattern of cylinder accelerations from the mostly good firing events and is then able to accurately detect deviations from that pattern Both the hard misfire algorithm and the pattern cancellation algorithm produce a deviant cylinder acceleration value, which is used in evaluating misfire in the Generic Misfire Processing section below 2011Powertrain Control/Emissions Diagnosis, 8/2010 1-170 Description and Operation Misfire Detection Monitor Due to the high data processing requirements, the HDR algorithms may be implemented by the PCM in a separate chip The chip carries out the HDR algorithm calculations and sends the deviant cylinder acceleration values to the PCM microprocessor for additional processing as described below The chip requires correct operation of the CKP and camshaft position (CMP) sensor inputs DTC P1336 sets if the chip detects noise on the CKP sensor input or if the chip is unable to synchronize with the missing tooth location DTC P1336 points to noise present on the CKP sensor input or a lack of synchronization between the CMP and CKP sensors Generic Misfire Processing The acceleration that a piston undergoes during a normal firing event is directly related to the amount of torque that cylinder produces The calculated piston/cylinder acceleration value(s) are compared to a misfire threshold that is continuously adjusted based on inferred engine torque Deviant accelerations exceeding the threshold are conditionally labeled as misfires The calculated deviant acceleration value(s) are also evaluated for noise Normally, misfire results in a nonsymmetrical loss of cylinder acceleration Mechanical noise, such as rough roads at high RPM with light load conditions, will produce symmetrical acceleration variations Cylinder events that indicate excessive deviant accelerations of this type are considered noise Noise-free deviant acceleration exceeding a given threshold is labeled a misfire The number of misfires are counted over a continuous 200 revolution and 1,000 revolution period The revolution counters are not reset if the misfire monitor is temporarily disabled such as for negative torque mode At the end of the evaluation period, the total misfire rate and the misfire rate for each individual cylinder is computed The misfire rate is evaluated every 200 revolution period (Type A) and compared to a threshold value obtained from an engine speed/load table This misfire threshold is designed to prevent damage to the catalyst due to sustained excessive temperature 899°C (1,650°F) for Pt/Pd/Rh advanced washcoat and 982°C (1,800°F) for Pd-only high tech washcoat If the misfire threshold is exceeded and the catalyst temperature model calculates a catalyst mid-bed temperature that exceeds the catalyst damage threshold, the MIL blinks at a Hz rate while the misfire is present If the threshold is again exceeded on a subsequent driving cycle, the MIL is illuminated If a single cylinder is determined to be consistently misfiring in excess of the catalyst damage criteria, the fuel injector to that cylinder is shut off to prevent catalyst damage for a calibrated period of time, typically 30 to 60 seconds Up to cylinders may be disabled at the same time on and cylinder engines and one cylinder on cylinder engines After the calibrated period of time has elapsed, the injector is re-enabled If misfire on that cylinder is detected again after 200 revolutions (about to 10 seconds), the fuel injector is shut off again and the process repeats until the misfire is no longer present Note that ignition coil primary circuit failures trigger the same type of fuel injector disablement For additional information, refer to Comprehensive Component Monitor (CCM) in this section 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-171 Misfire Detection Monitor The misfire rate is also evaluated every 1,000 revolution period and compared to a single (type B) threshold value to indicate an emission-threshold concern, which can be either a single 1,000 over-rev event from startup or subsequent 1,000 over-rev events on a drive cycle after start-up Many vehicles set DTC P0316 if the type B threshold is exceeded during the first 1,000 revolutions after engine startup This DTC is stored in addition to the normal P03xx DTC that indicates the misfiring cylinder If the misfire is detected but it can not be attributed to a specific cylinder, DTC P0300 is stored Rough Road Detection The misfire detection monitor may include a rough road detection system to eliminate false misfire indications due to rough road conditions The rough road detection system uses data from the anti-lock brake system (ABS) wheel speed sensors for estimating the severity of rough road conditions This is a more direct measurement of rough road over other methods which are based on drive line feedback via crankshaft velocity measurements It improves accuracy over these other methods since it eliminates interactions with actual misfire In the event of a rough road detection system failure, the rough road detection output is ignored and the misfire detection monitor remains active A rough road detection system failure could be caused by a failure in any of the input signals to the algorithm This includes the ABS wheel speed sensors, brake pedal sensor, or controller area network (CAN) hardware concerns Specific DTCs indicate the source of these component concerns A redundant check is also carried out on the rough road detection system to verify it is not stuck high due to other unforeseen causes If the rough road detection system indicates rough road during low vehicle speed conditions where it is not expected, the rough road detection output is ignored and the misfire monitor remains active Profile Correction Profile correction software is used to learn and correct for mechanical inaccuracies in the crankshaft position wheel tooth spacing Since the sum of all the angles between the crankshaft teeth must equal 360 degrees, a correction factor can be calculated for each misfire sample interval that makes all the angles between individual teeth equal The LDR system learns one profile correction factor per cylinder (that is, correction factors for a cylinder engine), while the HDR system learns 36 or 40 correction factors depending on the number of crankshaft wheel teeth (ex 36 for V6 or V8 engines, 40 for V10 engines) The corrections are calculated from several engine cycles of misfire sample interval data The correction factors are the average of a selected number of samples In order to assure the accuracy of these corrections, a tolerance is placed on the incoming values such that an individual correction factor must be repeatable within the tolerance during learning This is to reduce the possibility of learning corrections on rough road conditions which could limit misfire detection capability and to help isolate misfire diagnoses from other crankshaft velocity disturbances 2011Powertrain Control/Emissions Diagnosis, 8/2010 1-172 Description and Operation Misfire Detection Monitor To prevent any fueling or combustion differences from affecting the correction factors, learning is done during deceleration fuel shut-off (DFSO) This can be done during closed-throttle, non-braking, de-fueled decelerations in the 97 to 64 km/h (60 to 40 mph) range after exceeding 97 km/h (60 mph) (likely to correspond to a freeway exit condition) In order to minimize the learning time for the correction factors, a more aggressive deceleration fuel shut-off strategy may be used when the conditions for learning are present The corrections are typically learned in a single 97 to 64 km/h (60 to 40 mph) deceleration, but may take up to such decelerations or a higher number of shorter decelerations Since inaccuracies in the wheel tooth spacing can produce a false indication of misfire, the misfire monitor is not active until the corrections are learned In the event of battery disconnection or loss of keep alive memory (KAM), the correction factors are lost and must be relearned If the software is unable to learn a profile after three, 97 to 64 km/h (60 to 40 mph) deceleration cycles, DTC P0315 is set Neutral Profile Correction and Non-Volatile Memory Neutral profile learning is used at end of line to learn profile correction through a series of one or more neutral engine RPM throttle snaps This allows the misfire monitor to be activated at the assembly plant A scan tool command is required to enable neutral profile correction learning Learning profile correction factors at high-speed (3,000 RPM) neutral conditions versus during 60-40 mph decels optimizes correction factors for higher RPMs where they are most needed and eliminates driveline or transmission and road noise effects This improves signal to noise characteristics which means improved detection capability The profile correction factors learned at the assembly plant are stored into non-volatile memory This eliminates the need for specific customer drive cycles However, misfire profiles may need to be relearned using a scan tool procedure if major engine work is done or the PCM is replaced Re-learning is not required for a reflash The neutral profile correction strategy is only available on selected vehicles Misfire Detection Monitor Specifications Misfire detection monitor operation: DTCs P0300 to P0310 (random and specific cylinder misfire), P1336 (noisy crank sensor, no crankshaft/camshaft sensor synchronization), P0315 (crankshaft position system variation not learned), P0316 (misfire detected on startup [first 1000 revolutions]) The monitor execution is continuous, misfire rate calculated every 200 or 1,000 revolutions The monitor does not have a specific sequence The CKP, CMP, MAF, and ECT or CHT sensors have to be operating correctly to run the monitor The monitoring duration is the entire driving cycle (see disablement conditions below) Typical misfire detection monitor entry conditions: Entry condition minimum/maximum time since engine start-up is seconds, engine coolant temperature is -7°C to 121°C (20°F to 250°F), RPM range is (full-range misfire certified, with revolution delay) revolutions after exceeding 150 RPM below drive idle RPM to red line on tach or fuel cutoff, profile correction factors are learned in KAM, and the fuel tank level is greater than 15% Typical misfire temporary disablement conditions: Closed throttle deceleration (negative torque, engine being driven), Fuel shut-off due to vehicle-speed limiting or engine-RPM limiting mode, a high rate of change of torque (heavy throttle tip-in or tip out) and rough road conditions 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-173 Misfire Detection Monitor The profile learning operation includes DTC P0315, unable to learn profile in three, 97 to 64 km/h (60 to 40 mph) decelerations; monitor execution is once per profile learning sequence; The monitor sequence: profile must be learned before the misfire monitor is active; The CKP and CMP sensors are required to be OK; CKP/CMP signals must be synchronized The monitoring duration is 10 cumulative seconds in conditions (a maximum of three, 97 to 64 km/h (60 to 40 mph) de-fueled decelerations) Customer drive cycle typical profile learning entry conditions: Entry conditions from minimum to maximum: Engine in deceleration fuel shut-off mode for engine cycles, the brakes are not applied, the engine RPM is 1,300 to 3,700 RPM, the change is less than 600 RPM, the vehicle speed is 48 to 121 km/h (30 to 75 mph), and the learning tolerance is 1% Assembly plant or repair facility typical profile learning entry conditions: Entry conditions from minimum to maximum: Engine in deceleration fuel shut-off mode for engine cycles, the vehicle in park/neutral gear, the engine RPM is 2,000 to 3,000 RPM, the learning tolerance is 1% 2011Powertrain Control/Emissions Diagnosis, 8/2010 1-174 Description and Operation Positive Crankcase Ventilation (PCV) System Monitor The PCV monitor consists of a modified PCV system design The PCV valve is installed into the rocker cover using a quarter-turn cam-lock design to prevent accidental disconnection High retention force molded plastic lines are used from the PCV valve to the intake manifold The diameter of the lines and the intake manifold entry fitting are increased so inadvertent disconnection of the lines after a vehicle is repaired causes either an immediate engine stall or does not allow the engine to be restarted In the event the vehicle does not stall if the line between the intake manifold and PCV valve is inadvertently disconnected, the vehicle has a large vacuum leak that causes the vehicle to run lean at idle This illuminates the malfunction indicator lamp (MIL) after consecutive driving cycles and stores one or more of the following DTCs: Lack of HO2S sensor switches, bank (P2195), Lack of HO2S sensor switches bank (P2197), fuel system lean, bank (P0171) or fuel system lean, bank (P0174) The PCV monitor sets DTC P2282 if a PCV vacuum hose is disconnected, or if a large air leak between the throttle body and intake valves is present A fast idle speed symptom may be present when the DTC P2282 is set For additional PCV information, refer to Positive Crankcase Ventilation (PCV) System in this section 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-175 Thermostat Monitor The thermostat monitor is designed to verify correct thermostat operation This monitor is executed once per drive cycle and has a monitor run duration of 300-800 seconds If a concern is present, diagnostic trouble code (DTC) P0125 or P0128 is set and the malfunction indicator lamp (MIL) is illuminated The monitor checks the engine coolant temperature (ECT) or cylinder head temperature (CHT) sensor to warm up in a predictable manner when the engine is generating sufficient heat A timer is initialized while the engine is at moderate load and the vehicle speed is above a calibrated limit The target timer value is based on ambient air temperature at start-up If the timer exceeds the target time and ECT or CHT has not warmed up to the target temperature, a concern is indicated The test runs if the start-up intake air temperature from the intake air temperature (IAT) sensor is at, or below the target temperature A 2-hour engine off soak time is also required to enable the monitor and to prevent erasing of any pending DTCs during a hot soak This soak time feature also prevents false-passes of the monitor when the engine coolant temperature rises after the engine is turned off during a short engine off soak period The target temperature is calibrated to within 11°C (20°F) less than the thermostat regulating temperature For a typical 90°C (195°F) thermostat, the target temperature would be calibrated to 79°C (175°F) Some vehicle calibrations may lower the target temperature to less than 27°C (50°F) for vehicles that not warm-up to thermostat regulating temperatures in the 11°C (20°F) to 27°C (50°F) ambient temperature range Inputs: ECT or CHT, IAT, engine LOAD (from MAF sensor) and vehicle speed input Typical monitor entry conditions: • vehicle speed greater than 24 km/h (15 mph) • intake air temperature at start-up is between -7°C (20°F) and target thermostat temperature • engine load greater than 30% • engine off (soak) time greater than hours Output: MIL 2011Powertrain Control/Emissions Diagnosis, 8/2010 1-176 Description and Operation Thermostat Monitor Thermostat Monitor 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-177 Variable Camshaft Timing (VCT) Monitor The VCT output driver in the powertrain control module (PCM) is checked electrically for opens or shorts The VCT system is checked functionally by monitoring the closed loop camshaft position error correction If the correct camshaft position cannot be maintained and the system has an advance or retard error greater than the calibrated threshold, a VCT control concern is indicated For additional information, refer to Variable Camshaft Timing (VCT) System in this section 2011Powertrain Control/Emissions Diagnosis, 8/2010 ... cylinder) applications, the matched pairs are and 5, and 6, and and For 4-tower coil pack (4 cylinder) applications, the matched pairs are and and and When the coil is fired by the PCM, spark... Control/Emissions Diagnosis, 8/2010 1-4 Description and Operation Vehicle Emission Control Information (VECI) 2011Powertrain Control/Emissions Diagnosis, 8/2010 Description and Operation 1-5 Vehicle Certification... Diagnosis, 8/2010 Description and Operation 1-17 Engine Control Components Coil packs come in 4-tower, 6-tower horizontal and 6-tower series models Two adjacent coil towers share a common coil and are