Service Training The 2.
Audi of America, LLC Service Training Printed in U.S.A. Printed 7/2009 Course Number 922903 ©2009 Audi of America, LLC All rights reserved. Information contained in this manual is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of America, LLC., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice.
Table of Contents Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Engine Mechanicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Oil Circulation System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 SULEV 2.0L TFSI Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Service. . . . . . .
Notes ii
Introduction The turbocharged 2.0L 4V chain-driven AVS engine (CAEB) described in this Self-Study Program is a development of the 1.8L chain-driven engine (EA 888 family) introduced in Europe in 2006. The 1.8L engine, known as the Stage 0 engine, was the basis for the chain-driven 2.0L 4 cylinder engine (CCTA/CBFA) introduced in North America during the 2008 model year. This EA 888 family of engines is replacing the belt-driven camshaft engines within the Volkswagen Group world wide. The 2.
Introduction Technical Description Four Cylinder, Four Valve, FSI Turbocharged Gasoline Engine Engine Block Engine Management – Cast Iron Crankcase – MED 17 Engine Control – Balancer Shafts in Crankcase – Hot-Film Air Mass Flow with Integral Temperature Sensor – Forged Steel Crankshaft – Self-Regulating Sump-Mounted Oil Pump — Chain-Driven by Crankshaft – Timing Gear Chain — Front End of Engine – Balancer — Chain-Driven at Front End of Engine Cylinder Head – 4-Valve Cylinder Head – 1 INA Intake Camsha
Introduction Torque/Power Curve 201 (150) 265 (360) Power in hp (kW) Torque in lb ft (Nm) 243 (330) 220 (300) 161 (120) 200 (270) 177 (240) 121 (90) 155 (210) 133 (180) 80 (60) 110 (150) 88 (120) 67 (90) 40 (30) 44 (60) 22 (30) 0 0 0 1000 2000 3000 4000 5000 6000 7000 Engine Speed in RPM Specifications Engine Code Type of Engine Displacement CAEB Turbocharged Inline 4-Cylinder FSI Engine 121 cu in (1984 cm3) Maximum Power 200 hp (147 kW) @ 5100 – 6000 rpm Maximum Torque 206 lb ft (280
Engine Mechanicals Audi Valve Lift System (AVS) The Audi Valve Lift System (AVS) was developed to optimize the combustion charge cycle. AVS was introduced in the North American Region with the 3.2L V6 FSI engine in 2008. The AVS application on the turbocharged 2.0L CAEB engine is different from that of the 3.2L V6 AVS engine. On the 2.0L CAEB engine, AVS changes the lift and timing of the exhaust valves only. The firing order of the 2.0L CAEB engine is separated.
Engine Mechanicals The mechanical design and function of AVS on the 4-cylinder TFSI engine closely resembles the 6-cylinder naturally aspirated engine. However, different thermodynamic effects are used. At low engine speeds, a narrow profile cam lobe contour is used. At high engine speeds the AVS changes to a wider profile cam lobe contour. The narrow cam lobe contour provides very late exhaust valve opening.
Engine Mechanicals Modifications to the Roller Cam Followers The roller cam followers for the exhaust camshaft have been designed to reach both valve lift lobes on the cam elements. To achieve this, the roller is now larger in diameter and narrower in width. At the same time, the roller cam followers have been optimized for low friction by using improved bearings. To prevent the roller cam followers from tilting downward, they are permanently connected to the support element.
Engine Mechanicals Function Each cylinder has its own movable cam element mounted on the exhaust camshaft. Two valve lift contours are possible for each exhaust valve. Changing-over between the large and small cam lobe contours is achieved by the longitudinal displacement of the cam elements. The cam elements are moved on the exhaust camshaft by solenoid actuators. While one actuator switches from small valve lift to large valve lift, the other actuator switches from large valve lift to small valve lift.
Engine Mechanicals Cam Lobe Contour There are two cam lobe contours per valve on each cam element. The small cam lobes (shown in green) implement a valve opening stroke of 0.25 in (6.35 mm). The length of opening is 180° crankshaft angle. The exhaust valve closes 2° after TDC. The full stroke provided by the large cam lobes (shown in red) is 0.40 in (10 mm) with a length of opening of 215° crankshaft angle. The exhaust valve closes 8° before TDC.
Engine Mechanicals Camshaft Adjustment Actuators F366 – F373 The camshaft adjustment actuators are electromagnetic solenoid-type actuators. Two actuators are used per cylinder. One actuator moves the cam element on the camshaft for large valve lift. The other actuator resets the cam element for small valve lift. Each actuator is attached externally to the cylinder head cover by a bolt. They are sealed with O rings.
Engine Mechanicals Function A solenoid is integrated in the actuator. When the solenoid is activated by the ECM, a metal pin is extended. The solenoid is activated through brief application of battery voltage. When the metal pin is extended, it is held in position by a permanent magnet on the actuator housing. Due to the quick extension time (18 – 22 ms), the metal pin undergoes very rapid acceleration. A damping ring near the permanent magnet ensures that the pin does not bounce back or become damaged.
Engine Mechanicals Activation of the Cam Adjustment Actuators The Camshaft Adjustment Actuators are activated by the ECM, which provides a ground signal. Voltage to the actuators is supplied by Motronic Engine Control Module Power Supply Relay J271. The system is ready for operation above a coolant temperature of 14°F (–10°C). When the engine is started, the larger contour lobes are in position. Immediately after engine start, the system changes over to the smaller contour lobes.
Engine Mechanicals Changing Over Between Working Ranges The illustration below shows in schematic form the working range of the AVS when the engine is at operating temperature. In the engine speed range required for change-over to large valve lift, the intake manifold flaps are also opened wide. It can be seen that the small valve lift is used up to medium engine speeds of approximately 3100 rpm.
Engine Mechanicals Self-Diagnostics How the System Responds to Faults The engine self-diagnostics check the mechanical function of the cam adjustment actuators (changeover to the other cam lobe contour) and the system’s electrical connections. If one or more actuators fails, the ECM will initially attempt (several times) to change over to the other cam. If no adjustment is made, the cam elements that cannot be adjusted remain in position. A system test is performed after the engine is started.
Oil Circulation System Positive Crankcase Ventilation The following components were modified to achieve this goal: One of the goals in designing this new engine was to provide greater driver, passenger, and pedestrian safety in the event of a collision. For instance, the more compact design of the components above the cylinder head cover provides more clearance between the engine and hood. This translates to a larger crumple zone for the dissipation of energy upon impact.
Oil Circulation System Overview Breather Module Blow-By Inlet into the Intake Manifold (naturally aspirated mode) Blow-By Inlet into the Exhaust Turbocharger (charging mode) Blow-By Duct in Cylinder Head and in Cylinder Block Oil Return Duct in Cylinder Head, Cylinder Block and Oil Pan Oil Return Line Blow-By Gases from the Cylinder Block Non-Return Valve Oil Return Line Below the Dynamic Oil Level Reference The components are positioned differently, but have retained the same functions as on the 1.
Oil Circulation System Overview The oil circulation system of the 2.0L TFSI CAEB engine is unchanged from the CCTA/CBFA engine. The biggest difference between the two engines is the use of a new self-regulating oil pump on the CAEB engine.
Oil Circulation System Self-Regulating Oil Pump Oil Pressure Regulation Valve N428 A newly developed self-regulating engine oil pump is used on the 2.0L TFSI CAEB engine. The main purpose of this development is to increase pump operating efficiency and in turn, reduce fuel consumption. When compared to other self-regulating oil pumps, this design has a more efficient control concept.
Oil Circulation System Function Conventional Method of Control With a conventional oil pump, the delivery rate increases as the engine RPM increases. The oil consumers in the engine cannot process the excess oil being delivered, so the oil pressure increases. This is achieved by axial displacement of the cam lobe unit or in other words, by displacement of the oil pump gears relative to one another. The delivery rate is highest when both pump gears are aligned exactly opposite each other.
Oil Circulation System Positions of the Cam Lobe Unit No axial displacement: maximum oil flow rate Maximum axial displacement: low oil flow rate Engine Start-Up The illustration below shows how the oil pump functions when the engine is started. Engine oil passes through the pressure port on the filtered oil side and impinges on all surfaces of the control piston while flowing to both sides of the cam lobe unit.
Oil Circulation System Low Pressure Setting Reached If engine speed increases, the oil pressure increases slightly and displaces the control piston against the force of the regulating spring. The pressure port to the front piston face of the cam lobe unit closes. At the same time, the connection to the pressureless return line leading into the oil pan opens. The hydraulic force exerted by the rear piston face of the cam lobe unit is now greater than the spring force.
Oil Circulation System Change-Over Point to High Pressure Setting The system changes over to the high pressure setting at an engine speed of approximately 3500 rpm. Oil Pressure Regulating Valve N428 is de-energized for this. The oil pressure acting upon the front piston face and the compression spring push the cam lobe unit back again, so that both pump gears are again almost in parallel with one another and the pump is operating at its maximum delivery rate.
Oil Circulation System High Pressure Setting is Reached Oil Pressure Regulation Valve N428 remains de-energized. The force equilibrium between the control piston and regulating spring is maintained by the higher oil pressure (the effective piston surface area is smaller). As engine speed increases, the cam lobe unit again begins to move (as in the low pressure setting). The change-over to the high pressure setting is registered by O.3 Bar Oil Pressure Switch F22 (on the oil filter module).
Oil Circulation System Oil Pressure Switch One or two oil pressure switches are used, depending upon whether the engine is equipped with a selfregulating oil pump. Oil pressure switches are generally mounted on the oil filter module. Example: Comparison of Pressure Characteristics Relative Oil Pressure (psi / bar) Oil Temperature at 158°F (70°C) 73 (5) 58 (4) 2 44 (3) 1 29 (2) 14.5 (1) 1000 2000 3000 4000 5000 6000 7000 Engine speed [rpm] Pressure Requirements of 1.
Oil Circulation System Oil Pressure Monitoring Convenience CAN On engines with a self-regulating oil pump, oil pressure is monitored by two oil pressure switches. This is necessary because two different oil pressures are used.
Oil Circulation System Oil Pressure Monitoring In the ECM, oil pressure switches are monitored at engine ON and validated at engine OFF. Validation at Engine OFF There should NOT be a signal from a closed oil pressure switch when the engine is switched OFF. If there is, an electrical fault has occurred. At terminal 15 ON, a warning is indicated in the Driver Information System display (“red oil can” together with the fault text “Shut off engine and check oil level”).
SULEV 2.0L TFSI Engine Introduction With the introduction of the 2.0L CAEB engine, Audi was able to combine direct fuel injection, AVS, and turbocharging while still meeting the stringent ULEV II exhaust emission limits. However, some states require the even more stringent SULEV exhaust emission standards. The measures undertaken to comply with the SULEV exhaust emission regulations will be explained in detail on the following pages. The technical descriptions refer to the Audi A3.
SULEV 2.0L TFSI Engine Secondary Air System To reduce hydrocarbon emissions at the earliest possible stage, fresh air is blown into the cylinder head exhaust ports during the engine start phase. The system is designed to rapidly develop pressure and achieve a high delivery rate on activation. The illustration below shows the components of the secondary air system.
SULEV 2.0L TFSI Engine Secondary Air Injection Solenoid Valve N112 Unlike earlier valves, the newly developed Secondary Air Injection Solenoid Valve N112 operates electrically. It is mounted directly to the cylinder head by bolts. When compared to the pneumatic valves used previously, the secondary air intake valve is extremely rugged.
SULEV 2.0L TFSI Engine Secondary Air Injection Sensor 1 G609 Secondary Air Injection Sensor 1 G609 connects to the pressure line coupling upstream of Secondary Air Injection Valve N112. It supplies the ECM with an analog output signal of between 0.5 and 4.5 V. Its measurement window is between 7 and 22 psi (50 kPa – 150 kPa). Signal Utilization This signal is used for diagnosing the secondary air system. Because the system is relevant to exhaust emissions, legislation requires that it be monitored.
SULEV 2.0L TFSI Engine Testing the System The California Air Resources Board (CARB) requires that the secondary air system be monitored during the heatup phase of the catalytic converter. Previously, the system was monitored using the oxygen sensor. However, this downstream sensor does not become available quickly enough. For this reason, the system is monitored and evaluated for pressure-based secondary air diagnosis by Secondary Air Injection Sensor 1 G609.
SULEV 2.
SULEV 2.0L TFSI Engine Exhaust Turbocharger The turbocharger used on SULEV emission level engines is made of cast steel, and not cast iron. Cast steel provides excellent long-term stability. In addition, the components heat up more quickly after engine start-up because they have thinner walls. Both air flow and catalytic converter inflow have been greatly improved, reducing the exhaust gas backpressure upstream of the turbine.
SULEV 2.0L TFSI Engine Catalytic Converter System The exhaust system was developed with the following goals in mind: – Easy compliance with SULEV exhaust emission limits – High long-term stability over 150,000 miles (240,000 km) and 15 years – Minimized increase in exhaust back-pressure in catalytic converters with a high cell density The primary catalytic converter is designed to comply with statutory emission limits. To achieve this, cell density has been increased and wall thickness reduced.
SULEV 2.0L TFSI Engine Oxygen Sensors The oxygen sensors were designed to minimize the time-to-readiness for the closed-loop operation engine management system. G39 is located upstream of the primary catalytic converter. This sensor has an additional triple-layer protective tube. By installing the broadband oxygen sensor in the turbine housing, closed-loop operation can begin only 19 seconds after starting the engine. Two type LSU4.
SULEV 2.0L TFSI Engine Natural Frequency Based Oxygen Sensor Control Task The task of this system is to maximize utilization of the primary catalytic converter during the conversion of pollutant gases. Function Oxygen Sensor G130 LSF4.2 downstream of the primary catalytic converter supplies the ECM with a voltage signal (nonlinear) indicating “rich” or “lean.” Heated Oxygen Sensor G39 LSU4.9 determines a frequency from the flow rate and the condition of the catalytic converter.
SULEV 2.0L TFSI Engine Voltage in V Signal Characteristics of the Oxygen Sensors 0.65 Voltage in V 0.70 0.50 Lambda 0.30 1.02 0.
SULEV 2.0L TFSI Engine Automatic Starter Control in the Audi A3 To ensure that the Audi A3 easily achieves SULEV exhaust emission limits, an automatic starter control system is used. Starting Sequence The ECM does not allow fuel to be injected into the combustion chamber until a pressure of at least 870 psi (60 bar) is measured in the fuel rail at start-up. This pressure is necessary to keep raw hydrocarbon emissions to an absolute minimum.
SULEV 2.
SULEV 2.0L TFSI Engine Operating Modes After cold-starting the engine, various operating modes and fuel injection strategies are implemented: – Stratified start (high-pressure fuel injection) – Catalyst heating by homogeneous split dual injection, in conjunction with secondary air injection – Dual injection during the engine warm-up phase Stratified Start When the rail pressure exceeds 60 bar (absolute) the injection enable signal is issued by the ECM.
SULEV 2.0L TFSI Engine Catalyst Heating with Dual Injection and Secondary Air Injection – Fuel rail pressure – Injection timing of first injection during the intake phase – Injection timing of second injection during the compression phase Fuel Quantity [%] To achieve good idling quality, a special characteristic map has been selected.
SULEV 2.0L TFSI Engine Compliance with Statutory Limits (PremAir®) When evaluating the environmental compatibility of vehicles, the EPA awards “credits” for technical measures designed to improve air quality. These credits can be used to offset fleet emissions that are over the limit. For this reason, a radiator with a special catalytic coating is used on the Audi A3. This PremAir® technology* contributes to improving air quality. In exchange, the California Air Resources Board allows a higher NMOG* limit.
SULEV 2.0L TFSI Engine Function The entire cooling surface of the car’s radiator is coated with catalytic material. When air flows through this specially coated radiator, the ozone in the air is converted to oxygen (chemical symbol O2). Ozone (chemical symbol O3) is a gas which is harmful to health. Given that the air in a car radiator can flow at up to two kilograms per second, a car with a PremAir® radiator makes a significant contribution to reducing nearsurface ozone levels.
SULEV 2.
SULEV 2.0L TFSI Engine Temperature Sensor Diagnostics The temperature sensor is diagnosed in Engine Control Module J623 only. To prevent tampering, no tests can be performed using the VAS Scan Tool. Furthermore, the temperature signal is not transmitted as a voltage value, but as a LIN message. Before the ECM can diagnose the temperature sensor, several enabling conditions must be met. The values are then checked in multiple measurement windows.
Service Special Tools Here you can see the special tools for the 4-cylinder TFSI engines. T40191/1 (narrow) and T40191/2 (wide) spacers for locating the AVS spline ends on the camshaft T40196 adaptor for moving the AVS spline ends on the camshaft T10352 assembly tool for removing and installing the inlet camshaft timing adjustment valve. The “/1” tool has offset stud bolts. It is used upwards of a defined engine version.
EA 888 Engine Development Overview of the Development Stages Engine Stage 0 1.8L Longitudinal Engine 1.8L Transverse Engine EC: BYT SOP: 01/2007 EOP: 06/2007 Initial Rollout of the EA888 Engine Series 2.0L Longitudinal Engine 2.0L Transverse Engine You will find explanatory notes on the abbreviations used in this table on page 48.
EA 888 Engine Development Stage 1 Stage 2 EC: CABA SOP: 02/2008 EOP: 09/2008 EU IV EC: CDHA SOP: 09/2008 EOP: – / – EU V EC: CABB SOP: 07/2007 EOP: 05/2008 EU IV EC: CDHB SOP: 06/2008 EOP: – / – EU V EC: CABD SOP: 10/2007 EOP: 11/2008 EU IV Modifications to Stage 0 (1.
EA 888 Engine Development Technical Features Technical Features of the 4-Cylinder TFSI Engines Engine 1.8L TFSI 1.8L TFSI 1.8L TFSI CDHA, CABA BYT, BZB CDAA, CABB, CDHB 1789 1789 1789 Max. Power in kW @ rpm 88 @ 3650 – 6200 118 @ 5000 – 6200 118 at 4500 – 6200 Max. Torque in kW @ rpm 230 @ 1500 – 3650 250 @ 1500 – 4200 250 at 1500 – 4500 Bore in mm 82.5 82.5 82.5 Stroke in mm 84.1 84.1 84.1 Compression Ratio 9.6 : 1 9.6 : 1 9.
EA 888 Engine Development 1.8L TFSI 2.0L TFSI 2.0L TFSI 2.0L TFSI 2.0L TFSI CABD CAEA, CDNB, (CDNA)** CAWB, CBFA CCTA, CCZA CAEB, CDNC 1789 1984 1984 1984 1984 125 @ 4800 – 6200 132 @ 4000 – 6000 147 @ 5100 – 6000 147 @ 5100 – 6000 155 @ 4300 – 6000 250 @ 1500 – 4800 320 @ 1500 – 3900 280 @ 1700 – 5000 280 @ 1700 – 5000 350 @ 1500 – 4200 82.5 82.5 82.5 82.5 82.5 84.1 92.8 92.8 92.8 92.8 9.6 : 1 9.6 : 1 9.6 : 1 9.6 : 1 9.
Notes 50
Knowledge Assessment An on-line Knowledge Assessment (exam) is available for this Self-Study Program. The Knowledge Assessment may or may not be required for Certification. You can find this Knowledge Assessment at: www.accessaudi.com From the accessaudi.com Homepage: – Click on the “ACADEMY” tab – Click on the “Academy Site” link – Click on the “CRC/Certification” link – Click on Course Catalog and select “922903 — Audi 2.
