Ответ: Немного инфы по МОТРОНИКУ на ADU/AAN/ABY/3B http://members.aol.com/c1j1miller/ecu.html <CENTER>[size=+3]ECU (Motronic) and Sensors[/size]</CENTER>[size=-2]Last updated June 8, 1998[/size]<HR width="100%"> I thought I'd prepare a page describing the 20-valve turbo engine used in the '91 200q, and its various sensors and control units. Most of this information is based on the Audi Service Training Self-Study Informatin booklet entitled "The New 20V Turbo Engine for the Audi 200 Quattro", WSP-521-209-00. Add/read comments on the contents of this page. <HR width="100%"> The Motronic control unit (ECU) performs the following functions: Sequential Fuel Injection Basic fuel mixture control via a map in the ECU memory Starting enrichment After-start enrichment Warm-up enrichment Acceleration enrichment Deceleration fuel shut off Engine speed limitation Oxygen sensor control Ignition Timing Control Basic timing control via an ignition map in the ECU memory Dwell angle control Ignition timing corrections based on air temperature Start control Warm-up correction Digital idle stabilization Cylinder-selective knock control Boost Pressure Control Boost pressure control via a map in the ECU memory with adaptive learning capacity Starting correction Idle speed increase with A/C Fuel Tank Ventilation Fuel tank vapor flow control via a map in the ECU memory Frequency valve operation controlled via a map in the ECU memory Self Diagnostics Monitors sensor inputs Monitors outputs Fault output via VAG 1551 scan tool Display individual values via VAG 1551 Perform output checks Emergency mode operation <HR width="100%"> Hall Sender (G 40) in the distributor The signal from the Hall sender is used to: Provide the ignition firing point for the #1 cylinder when the engine is first started Determine injection timing and sequence Provide the cylinder reference signal for the knock sensors If the Hall sensor fails, the engine cannot be restarted. If the Hall sender fails when the engine is running, the engine will continue to run by using the reference sensor and engine speed sensor signals, but the timing is retarded by 6°. <HR width="100%"> Reference Mark Sensor (G4) and Engine Speed Sensors (G28) The two sensors are identical in design and are located on the left side of the engine compartment, near the flywheel. The reference sensor is used by the ECU to identify the crankshaft position. A steel pin is pressed into the flywheel 62° before Top Dead Center (TDC) for the #1 cylinder. The pin, along with the sensor, generate one signal per crankshaft revolution. The speed sensor produces an alternating current (AC) voltage signal by scanning the teeth of the flywheel. This signal is used by the control unit to measure engine speed. If either of the sensors fail, the engine cannot be started. However, if the reference sensor fails when the engine is running, the system will use the #1 cylinder signal that was used when the engine was started. <HR width="100%"> Air Mass Sensor (G70) (Hot Wire Mass Airflow Sensor) A hot wire air mass sensor is located ahead of the turbocharger mounted after the air filter housing. The sensor is used to measure the air flow into the engine. The sensor uses a glass-coated thin platinum wire to measure the air flow. A baffle screen is installed prior to the air mass sensor to reduce air turbulence at the measuring point. The platinum wire inside the sensor is heated electronically. An air temperature sensor is used to determine the amount of current to heat the platinum wire. As air flows over the heated wire, the wire is cooled, which changes the resistance of the wire. The ECU uses this resistance change to calculate air flow volume and air density. In this way, the actual volume of air is calculated by its mass. This measurement will not require additional corrections because it already accounts for any possible changes in air tempertature and/or air pressure. The voltage signal from the mass air flow sensor is used as an engine load signal. This load signal is a major input variable for all load and speed dependant calculations such as ignition timing, injection time, activation of the evaporative emmission (carbon canister) frequency valve, and idle speed adaptation. When starting the engine, the low air flow makes the signal from the mass air flow sensor not accurate enough. Therefore, additional information from other sensors are used such as barometric pressure and temperature dependant fixed values when starting the engine. Since contamination of the hot wire surface can cause inaccurate readings, the hot wire is heated electrically to a temperature of 1,000°C (1,810° F) for one second each time the engine is switched off to burn off contaminants. The burnoff signal is provided by the ECU. Due to this fact, it is important to not remove the connector plug from the ECI within 20 seconds of switching off the ignition. No repairs can be made to the Air Mass Sensor. If the Air Mass Sensor fails, the engine will continue to run as follows: When the throttle is closed (idle switch on the throttle plate closed), the engine runs at the idle ignition timing map in the ECU with a preprogrammed amount of air assumed. When the idle switch is opened (part load), the ignition timing goes to a fixed position of 20° and the fuel mixture is leaned. This will allow driving the vehicle to the repair shop. <HR width="100%"> Throttle Valve Potentiometer (G69) with Idle Switch (F60) An idle switch and throttle valve potentiometer are used on the throttle body assembly. The idle switch closes at approximately 1.3° before the throttle plate closes. When the switch is closed, this signal is used to activate the following functions: Idle stabilization Decelleration fuel shut-off with the engine warm and above 1,400 RPM. Fuel supply is reactivated when the engine speed falls below 1,200 RPM. Special ignition map for deceleration The throttle valve potentiometer is connected to the throttle shaft and is supplied 5 volts. The signal it provides is used to determine the position of the throttle plate and the speed of the throttle plate movement. The throttle valve potentiometer is only used for boost regulation. The throttle valve position is a reference value for the boost control map. Boost regulation will only occur when the throttle plate is open more than 35°. The Motronic system does not use a full throttle switch. The control unit detects full load on the relationship of engine load to engine speed. If the idle switch should fail, the idle stabilization system will not operate. If the potentiometer should fail, boost pressure is controlled mechanically by the wastegate at a lower value than what is programmed in the ECU. <HR width="100%"> Intake Air Temperature Sensor (G42) An air temperature sensor is located in the intake manifold near the throttle valve housing. It is used for ignition timing, knock regulation, and boost pressure control. The sensor is a positive temperature coefficient (PTC) resistor. The ignition timing adapts to current intake air temperature. As the intake air temperature increases, the boost pressure is reduced to prevent detonation. If the sensor should fail, the ignition timing is retarded and a replacement value of 40° C is used for boost regulation. <HR width="100%"> Coolant Temperature Sensor (G62) A coolant temperature sensor is located at the back of the cylinder head. It is an NTC resistor. The sensor is used for ignition timing, injection timing during cold and hot starting, warm-up enrichment, and idle stabilization. If the coolant temperature sensor should fail, a substitute value is used based on a signal from the air temperature sensor: Air temperature greater than 0° C (32° F), the substitute value is 80° C (176° F) Air temperature less than 0° C, the substitute value is the intake air temperature for three minutes, and then switched to 80° C. <HR width="100%"> Knock Sensor I (G61) and Knock Sensor II (G66) Engine knock indicates increased thermal and mechanical load of the engine. When an engine starts to knock is determined by the compression ratio, fuel/air mixture, fuel quality/octane, and engine temperature. The 20-valve turbo uses two knock sensors. Knock sensor I is located next to cylinder #2 and is used for cylinders #1, #2, and #3. Knock sensor II is located next to cylinder #4 and is used for cylinders #4 and #5. The use of two knock sensors makes it possible for the system to be more sensitive to knock. The use of two sensors allows the ECU to detect the slightest knocking noise and which cylinder caused the knock. The ECU can then retard the timing for that individual cylinder, depending on engine temperature and boost pressure. If knocking is detected for an extended period of time, the ignition timing is retarded and the boost pressure is reduced. Ignition timing is retarded in 3° increments. Should knock continue after timing retard, the ECU will enrich the fuel mixture to reduce the combustion temperature; should knock continue, the ECU will then reduce boost pressure to a predetermined level. When knock has been eliminated, the ignition timing is returned to its normal value in 1.3° increments and boost pressure is returned to its normal value. If knock sensor I should fail, the ignition timing for cylinders #1, #2, and #3 are retarded by 6°. Similarly, if knock sensor II should fail, the timing for cylinders #4 and #5 are retarded by 6°. <HR width="100%"> Oxygen Sensor (G39) The Oxygen sensor (lambda sensor) is a heated unit. The sensor is located in the exhaust outlet for the turbocharger. The sensor measures oxygen content in the exhaust gas and is used to regulate the fuel/air mixture. When the engine is idling and at partial load, the air/fuel mixture is regulated to lambda (1 kg. fuel to 14 kg. air) to ensure optimal catalytic converter efficiency. The control system is adaptive; it is capable of replacing standard control values with modified values due to changes in the operating conditions. For example: the oxygen sensor in the exhaust manifold senses that the fuel mixture is too rich (too much fuel); the control unit changes the fuel mixture to a leaner value by shortening the injector opening time. If the mixture is still too rich and the control unit's rich limit is exceeded, the control unit will adapt to this condition and establish a new basic setting. This new basic setting (pilot value) will then be used in both open and closed loop engine operation. This eliminates the need for periodic CO adjustments. If the sensor should fail, the engine will run on the adapted fuel mixture at the point of failure. <HR width="100%"> Altitude Sensor (F96) The altitude sensor is located beneath the left kick panel, near the A pillar. When there is a change in the air pressure, the barometric cell in the altitude sensor moves a sliding contact over a set of resistors. This informs the ECU of the current ambient air pressure or altitude. The altitude sensor is only used for boost pressure control. At altitudes above 3,300 feet above sea level, the boost pressure is reduced as the altitude is increased. The reason for this is to avoid over-revving the turbocharger. If the sensor should fail, an altitude of 13,124 is assumed and the boost pressure is reduced to its minimum level. <HR width="100%"> Intake Manifold Pressure Sensor (G71) The intake manifold pressure sensor (located in the ECU) is used to measure the amount of boost pressure in the intake manifold. A vacuum line from the intake manifold to the control unit is used to transmit manifold pressure/vacuum. The ECU converts this into an electrical signal. The sensor consists of a crystal ship and two semiconductors. The crystal is shaped in such a way that it allows a small amount of vacuum to be trapped between the base plate and the crystal. The crystal will flex depending on the amount of manifold pressure. The two semiconductors attached to the top of the crystal sense the flexing. The flexing of the chip cause the semiconductors to alter their shape. This changes the resistance value of the semiconductors. The change in resistance values is used by the control unit to determine the amount of boost pressure. <HR width="100%"> Multi-Function Temperature Sensor (F76) The multi-function temperature sensor is located in the coolant flange on the cylinder head. This sensor has several functions: When coolant temperature exceeds 119°C (245°F), the boost pressure is reduced. Engine temperature guage. Engine temperature warning light. Climate control compressor clutch operation. <HR width="100%"> Additional Signal: A/C Compressor ON/OFF Signal When the A/C compressor is switched on, a signal is sent to the ECU via pin #40. This signal is used to increase the rest position (closing value) for the idle stabilizer valve when the idle switch is open. This function reduces load slap by the A/C compressor. <HR width="100%"> Additional Signal: A/C Compressor Idle Speed Increase Signal When the A/C is switched on, pin #41 of the ECU receives a signal that the A/C is on. This increases the duty cycle to the idle stabilizer and raises the idle speed. <HR width="100%"> Idle Stabilizer Valve (N71) The idle stabilizer consists of a small single winding electric motor, rotary valve, and a return spring attached to the motor's armature. The motor is operated by a cycled DC voltage which will cause the armature to work against the return spring. The duty cycle determines the position of the rotary valve and the size of the opening. If the valve should fail, the engine runs with a constant quantity of air at idle, which is the same idle speed as if the valve was unplugged electrically. <HR width="100%"> Carbon Canister Frequency Valve (N80) and Carbon Canister Solenoid valve 034 133 517 "Vapor canister purge valve" Vapors from the fuel tank are collected in the carbon canister. A frequency valve is used to regulate the flow of fuel vapors that are drawn into the intake manifold from the carbon canister. The carbon canister is located on the right side of the car in front of the "A" pillar. The frequency valve is operated by the ECU. The valve is controlled by a duty cycle. The duty cycle will vary depending on engine temperature, oxygen sensor signal, load and speed. When the engine is off, a check valve stops the flow of vapors from entering the engine. This keeps the fuel vapors from entering the intake manifold and causing a rich mixture on restart. If power to the frequency valve is interupted or cut off completely when the engine is running, vacuum from the engine will open the check valve to allow tank ventilation. <HR width="100%"> Fuel Pump Relay (J17) and Fuel Pump Pump 8A09060916 $162.80 (Bosch 0 580 254 038) Fuel Line 4A02013516 $56.32 Adaptor sleeve 441201791 $10.16 The fuel pump is mounted within the fuel tank, and is activated by the fuel pump relay. The ECU supplies a ground signal to the fuel pump relay when the engine speed is greater than 25 rpm. <HR width="100%"> Fuel Pressure Regulator The fuel pump supplies fuel to the fuel filter, then, via a fuel rail, to the injectors. The fuel returned from the injecors is routed through the fuel pressure regulator. The diaphram-type fuel pressure regulator maintains fuel pressure at approximately 3 bar (43.5 psi) above the intake manifold pressure. A vacuum line from the intake manifold to the pressure regulator is used to transmit the varying intake manifold pressures. At idle, only a small quantity of fuel is needed to maintain engine operation. Vacuum from the intake manifold is applied to the diaphram and spring in the pressure regulator which allows more fuel to return to the fuel tank to maintain the correct fuel pressure. When the engine is under full load, the fuel consumption is greater. Manifold pressure is increased due to boost pressure from the turbo. This pressure closes the diaphram in the pressure regulator, allowing less fuel to return to the fuel tank to maintain the correct fuel pressure. When the engine is switched off, the diaphram in the pressure regulator is completely closed due to spring pressure. This creates a holding pressure between the pressure regulator and the fuel pump. <HR width="100%"> Sequential Injection The ECU uses a sequential injection similar to the MPI system used on the 20-valve normally aspirated engine in the Coupe and 90 Quattro. The ECU triggers the fuel injectors sequentially in the firing order of the engine (5-3-1-2-4). Each injector is triggered 360° before the ignition firing pint. The control unit operates the injectors by completing a ground circuit. The fuel mixture is determined by the duration (or length of time) that the injectors are held open. <HR width="100%"> Fuel Injectors (N30, N31, N32, N33, N83) One fuel injector is assigned to each cylinder. Each injector is located in the intake manifold, ahead of the intake valve. The injectors are electromagnetic single jet nozzle type, and consist of a valve housing, needle jet, and armature. The housing contains the solenoid winding, and the guide for the needle jet. When a ground is supplied to the solenoid wiring by the ECU, the needle jet is pulled away from the seat and the pressurized fuel exits the injector. The ECU registers faults in the injector circuit (break/short to ground, and short to positive). <HR width="100%"> Ignition Coil (N), Ignition Output Stage (N70), and Distributor (0) An ignition coil with a separate power stage is used with the Motronic system. The power stage is a Darlington type of transistor which switches the primary current for the ignition coil on and off. The power stage completes a ground circuit for terminal #1 of the ignition coil when it receives a voltage signal from the ECU. The distributor is mounted on the end of the cylinder head and is driven by the intake camshaft. <HR width="100%"> Additional Signal: Tachometer/Trip Computer The control unit supplies an engine speed signal for the tachometer and trip computer through pin #6. <HR width="100%"> Additional Signal: Fuel Consumption The ECU provides a fuel consumption signal for the trip computer through pin #32. The signal is calculated directly from injector timing. <HR width="100%"> Boost Pressure Control The purpose of boost pressure control is to ensure optimum boost pressure conditions throughout the entire operating range of the engine. Four components are used to regulate boost pressure: A bypass valve; Wastegate; Wastegate Frequency Valve; and the ECU <HR width="100%"> Bypass Valve Throttle overrun cutoff valve 034 145 710C (Bosch 0 280 142 106). The bypass valve, operated by intake manifold vacuum, is used to reduce the boost pressure in the intake air duct when the throttle plate is closed such as at idle or when decelerating. During idle or deceleration with the throttle valve closed, the bypass valve is opened by vacuum against spring pressure. When the valve is open, intake air is recirculated and the turbo is free to spin, but doesn't develop boost pressure. The bypass valve also maintains a higher turbo speed when the throttle is closed, which improves the response characteristics of the turbocharger when accelerating. <HR width="100%"> Wastegate Frequency Valve (N75) 034 906 283 F 1989 - 1991 RR engine in ur quattro & 200 3B engine 034 906 283 H 1991/1992 ABY engine and AAN Engines in S4/S6 034 906 283 J 3B engine in early S2 034 906 283 K ADU and ABY engines in late S2 and RS2 The wastegate frequency valve, located near the turbocharger and intake air duct, regulates the flow of intake manifold pressure to the wastegate, and is operated by the ECU. The frequency valve is operated by a duty cycle (pulsed ground) of 0-100%. By regulating the frequency valve's duty cycle, the control unit can regulate the boost pressure to match the predetermined value from the map in the ECU. Depending on the amount of charge pressure, the frequency valve will either increase the amount of charge pressure to the lower chamber of the wastegate to lower charge pressure (opening the wastegate), or, vent charge pressure to the inlet side of the turbocharger to raise charge pressure (allowing the wastegate to remain closed). If the wastegate frequency valve should fail, the boost pressure is controlled at a lower value mechanically by the wastegate. Self diagnostics recognizes two faults; break/short to ground, and short to positive. Additionally, a fault code will be stored if the maximum charge pressure is exceeded. If this occurs, the charge pressure control is switched off. The engine rev limited will be activated in the event of extremely high charge pressure. <HR width="100%" SIZE=6> Back to Chris Miller's main Audi page Back to the Repair Index Add/read comments on the contents of this page.All rights to this info in this format are reserved; feel free to use it, but don't just copy it verbatim! Not responsible for screwups in typing etc. YMMV, etc. I haven't tried many of these procedures, and some are adapted from procedures for other Audi models. Please send me any comments, updated procedures, etc. Chris Miller