Torque-based ETC also results in less intrusive vehicle and engine speed limiting, along with smoother traction control.

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1 VARIABLE CAM TIMING SYSTEM 2009 Ford Pickup 5.4L Eng F150 RELATED INFORMATION Overview [ Torque-Based Electronic Throttle Control (ETC) ] The torque-based ETC is a hardware and software strategy that delivers an engine output torque (via throttle angle) based on driver demand (pedal position). It uses an electronic throttle body, the powertrain control module (PCM), and an accelerator pedal assembly to control the throttle opening and engine torque. Torque-based ETC enables aggressive automatic transmission shift schedules (earlier upshifts and later downshifts). This is possible by adjusting the throttle angle to achieve the same wheel torque during shifts, and by calculating this desired torque, the system prevents engine lugging (low RPM and low manifold vacuum) while still delivering the performance and torque requested by the driver. It also enables many fuel economy/emission improvement technologies such as variable camshaft timing (VCT), which delivers same torque during transitions. Torque-based ETC also results in less intrusive vehicle and engine speed limiting, along with smoother traction control. Other benefits of torque-based ETC are: eliminate cruise control actuators eliminate idle air control (IAC) valve better airflow range packaging (no cable) more responsive powertrain at altitude and improved shift quality The ETC system illuminates a powertrain malfunction indicator (wrench) on the instrument cluster when a concern is present. Concerns are accompanied by diagnostic trouble codes (DTCs) and may also illuminate the malfunction indicator lamp (MIL). Overview [ Variable Camshaft Timing (VCT) System ] The VCT system enables rotation of the camshaft(s) relative to the crankshaft rotation as a function of engine operating conditions. There are four types of VCT systems. Exhaust phase shifting (EPS) system - the exhaust cam is the active cam being retarded. Intake phase shifting (IPS) system - the intake cam is the active cam being advanced. Dual equal phase shifting (DEPS) system - both intake and exhaust cams are phase shifted and equally advanced or retarded. Dual independent phase shifting (DIPS) system - where both the intake and exhaust 1/11

2 cams are shifted independently. All systems have four operational modes: idle, part throttle, wide open throttle (WOT), and default mode. At idle and low engine speeds with closed throttle, the powertrain control module (PCM) determines the phase angle based on air flow, engine oil temperature and engine coolant temperature. At part and wide open throttle the PCM determines the phase angle based on engine RPM, load, and throttle position. VCT systems provide reduced emissions and enhanced engine power, fuel economy and idle quality. IPS systems also have the added benefit of improved torque. In addition, some VCT system applications can eliminate the need for an external exhaust gas recirculation (EGR) system. The elimination of the EGR system is accomplished by controlling the overlap time between the intake valve opening and exhaust valve closing. Currently, both the IPS and DEPS systems are used. The VCT system knocking and noise concerns are diagnosed in the appropriate Service Information. For additional information, refer to the appropriate Engine System - General Information. Verification of incorrect VCT phasing on a warm engine operating below 1500 RPM can be isolated using a stethoscope and by monitoring the VCTADV, VCTADVERR and VCTDC PIDs using a scan tool. If the VCT phaser does not maintain correct valve timing, low oil pressure or oil flow restrictions are primary possible causes. Verify correct oil pressure and flow, refer to the appropriate Engine System - General Information. PID DESCRIPTION PID VCTADV VCT FAULT VCTADVERR VCTDC VCTSYS Description Monitors the VCT advance and displays the advance angle in degrees. The actual camshaft position is measured using the camshaft position (CMP) sensor. Displays YES or NO to indicate a VCT related concern is detected. The CMP circuit DTCs cause the VCT advance to default to 0. Correct any CMP DTCs prior to diagnosing engine timing or VCT DTCs. Displays the error in VCT advance. VCTADVERR uses the CMP signal to determine the difference between the actual camshaft position and the camshaft advance requested. The difference is displayed as a percentage that ranges from -5 to +5 %. When the accelerator pedal is cycled this may range as high as 20 %. Variable camshaft timing duty cycle ranges from 0 to 100%. The PCM controls the VCT solenoid operation through the duty cycled ground. Variable camshaft timing system displays whether the engine is in open or closed loop. In open loop, the PCM defaults the VCT system to off (0% duty cycle). In closed loop, the PCM turns the VCT system to ON (varies the VCT duty cycle). If a VCT DTC is detected, the VCT system defaults to open loop operation. Camshaft Position (CMP) Sensor The CMP sensor detects the position of the camshaft. The CMP sensor identifies when piston number 1 is on its compression stroke. A signal is then sent to the PCM and used for synchronizing the sequential firing of the fuel injectors. Coil on plug (COP) ignition applications use the CMP 2/11

3 signal to select the correct ignition coil to fire. Vehicles with two CMP sensors are equipped with variable camshaft timing (VCT). The second sensor is used to identify the position of the camshaft on bank 2. There are two types of CMP sensors: the 2-pin variable reluctance type sensor and the 3-pin Halleffect type sensor. Fig 1: Typical Variable Reluctance CMP Sensor Fig 2: Typical Hall-Effect CMP Sensor Comprehensive Component Monitor (CCM) The CCM monitors for concerns in any powertrain electronic component or circuit that provides input or output signals to the powertrain control module (PCM) that can affect emissions and is not monitored by another on board diagnostics (OBD) monitor. Inputs and outputs are, at a minimum, monitored for circuit continuity or correct range of values. Where feasible, inputs are also checked for rationality, and outputs are also checked for correct functionality. The CCM covers many components and circuits and tests them in various ways depending on the hardware, function, and type of signal. For example, analog inputs such as throttle position or engine coolant temperature are typically checked for opens, shorts, and out-of-range values. This type of monitoring is carried out continuously. Some digital inputs like brake switch or crankshaft position rely on rationality checks that are checking to see if the input value makes sense at the current engine operating conditions. These types of tests may require monitoring several components and can only be carried out under the appropriate test conditions. 3/11

4 Outputs such as coil drivers are checked for opens and shorts by monitoring a feedback circuit or smart driver associated with the output. Other outputs, such as relays, require additional feedback circuits to monitor the secondary side of the relay. Some outputs are also monitored for correct function by observing the reaction of the control system to a given change in the output command. An idle air control solenoid can be functionally tested by monitoring the idle RPM relative to the target idle RPM. Some tests can only be carried out under the appropriate test conditions. For example, the transmission shift solenoids can only be tested when the PCM commands a shift. The following is an example of some of the input and output components monitored by the CCM. The component monitor may belong to the engine, ignition, transmission, air conditioning, or any other PCM supported subsystem. 1. Inputs: Air conditioning pressure (ACP) transducer sensor, camshaft position (CMP) sensor, crankshaft position (CKP) sensor, engine coolant temperature (ECT) sensor, engine oil temperature (EOT) sensor, fuel rail pressure temperature (FRPT) sensor, fuel tank pressure (FTP) sensor, intake air temperature (IAT) sensor, mass air flow (MAF) sensor, throttle position (TP) sensor. 2. Outputs: EVAP canister purge valve, EVAP canister vent (CV) solenoid, fuel injector, fuel pump (FP), idle air control (IAC), intake manifold runner control (IMRC), shift solenoid, torque converter clutch (TCC) solenoid, variable camshaft timing (VCT) actuator, wide open throttle A/C cutout (WAC). 3. The CCM is enabled after the engine starts and is running. A diagnostic trouble code (DTC) is stored in keep alive memory (KAM) and the malfunction indicator lamp (MIL) is illuminated after 2 driving cycles when a concern is detected. Many of the CCM tests are also carried out during an on-demand self-test. Fig 3: Comprehensive Component Monitor (CCM) 4/11

5 Engine Assembly Fig 4: Identifying Engine Assembly ITEM DESCRIPTION Item Part Number Description Oil filter 5/11

6 2 6A642 Oil cooler (if equipped) Engine Oil Pressure (EOP) switch Oil filter adapter Oil pump screen and pickup tube Oil pump 7 6L266A Timing chain tensioner - RH 8 6C260 Variable Camshaft Timing (VCT) housing - RH 9 6M280 VCT oil control solenoid assembly - RH 10 6B284 Front camshaft bearing cap - RH 11 6L266B Timing chain tensioner - LH 12 6C261 VCT housing - LH 13 6M280 VCT oil control solenoid assembly - LH 14 6B284 Front camshaft bearing cap - LH Cylinder head - LH Engine Oil Temperature (EOT) Sensor The EOT sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the temperature increases and the resistance increases as the temperature decreases. The varying resistance changes the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature. Thermistor-type sensors are considered passive sensors. A passive sensor is connected to a voltage divider network so that varying the resistance of the passive sensor causes a variation in total current flow. Voltage that is dropped across a fixed resistor in a series with the sensor resistor determines the voltage signal at the PCM. This voltage signal is equal to the reference voltage minus the voltage drop across the fixed resistor. The EOT sensor measures the temperature of the engine oil. The sensor is typically threaded into the engine oil lubrication system. The PCM can use the EOT sensor input to determine the following: On variable camshaft timing (VCT) applications the EOT input is used to adjust the VCT control gains and logic for camshaft timing. The PCM can use EOT sensor input in conjunction with other PCM inputs to determine oil degradation. The PCM can use EOT sensor input to initiate a soft engine shutdown. To prevent engine damage from occurring as a result of high oil temperatures, the PCM has the ability to initiate a soft engine shutdown. Whenever engine RPM exceeds a calibrated level for a certain period of time, the PCM begins reducing power by disabling engine cylinders. 6/11

7 Fig 5: Typical EOT Sensor LH Variable Camshaft Timing (VCT) Housing, VCT Solenoid And Timing Chain Tensioner 7/11

8 Fig 6: Identifying LH Variable Camshaft Timing (VCT) Housing, VCT Solenoid And Timing Chain Tensioner ITEM DESCRIPTION Item Part Number Description 1 6L266B Timing chain tensioner - LH 2 6C261 Variable Camshaft Timing (VCT) housing - LH 3 6M280 VCT oil control solenoid assembly - LH Normal Operation Oil is drawn into the oil pump through the oil pump screen and pickup tube in the sump of the oil 8/11

9 pan. Oil is pumped through the oil filter on the left front side of the cylinder block then enters the main gallery where it is distributed to the crankshaft main journals and to both cylinder heads. From the main journals, the oil is routed through cross-drilled passages in the crankshaft to lubricate the connecting rod bearings. Controlled leakage through the crankshaft main bearings and connecting rod bearings is slung radially outward to cool and lubricate the cylinder walls as well as the entire connecting rod, piston and piston ring assembly. The left cylinder head is fed from a drilling into the supply passage feeding the main gallery at the front of the cylinder block. The right cylinder head is fed from a drilling into the rear of the main gallery. Main gallery pressure is reduced as it enters the cylinder head galleries through fixed serviceable orifices, located at the upper part of the feed passages. It is this reduced pressure in the cylinder head galleries which feed the camshaft journals, the hydraulic lash adjusters and the primary and secondary timing chain tensioners. On Variable Camshaft Timing (VCT) equipped engines, the oil pressure feed for the VCT solenoids, VCT housings and camshaft phaser and sprockets is not reduced. The camshaft lobe and roller followers are lubricated by splash created through valve train operation. This pinpoint test is intended to diagnose the following: Excessive crankshaft end play Excessive main bearing clearance Excessive connecting rod bearing clearance Excessive camshaft bearing cap clearance Loose camshaft phaser and sprocket bolt(s) [VCT engines only] Loose oil galley plugs Loose timing chain tensioner bolts Loose VCT housing bolts [VCT engines only] Oil pump screen and pickup tube Restricted oil flow passages Worn or damaged oil pump RH Variable Camshaft Timing (VCT) Housing And VCT Solenoid 9/11

10 Fig 7: Identifying RH Variable Camshaft Timing (VCT) Housing And VCT Solenoid ITEM DESCRIPTION Item Part Number Description 1 6M280 Front camshaft bearing cap - RH 2 6C261 Variable Camshaft Timing (VCT) housing - RH 3 6C260 VCT oil control solenoid assembly - RH Variable Camshaft Timing (VCT) Housing 10/11

11 Fig 8: Identifying Variable Camshaft Timing (VCT) Housing ITEM DESCRIPTION Item Part Number Description 1 - Variable Camshaft Timing (VCT) oil control solenoid assembly 2 - VCT housing 11/11