BMW 3 of the E46 series

since 1998 release

Repair and operation of the car

BMW 3 of the E46 series
+ BMW 3 Cars (E46)
+ Current leaving and service
+ Engine
+ Cooling systems, heating
+ Power supply systems, injection and release
- Electric equipment of the engine
   General information and security measures
   - System of electronic control by ignition and injection of the petrol engine
      The main data on system of electronic control by the engine
   + System of ignition
   + System of preheat of the diesel engine
   + Systems of a charge and start
+ RKPP and transmission line
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment

System of electronic control by ignition and injection of the petrol engine

The main data on system of electronic control by the engine

System of an electronic digital control petrol engine (DME)

1 — an adsorber
2 — the locking valve
3 — the valve of ventilation of a fuel tank
4 — the fuel pressure regulator
5 — an injector
6 — pressure zadatchik
7 — the ignition coil
8 — the situation sensor
9 — the pump of secondary air
10 — the locking valve
11 — the measuring instrument of mass of air
12 — a monitor
13 — the sensor of a butterfly valve

14 — an idling zadatchik
15 — the air temperature sensor
16 — the valve of recirculation of the fulfilled gases
17 — the fuel filter
18 — the detonation sensor
19 — the sensor of number of turns
20 — the engine temperature sensor
21 — the oxygen sensor
22 — the diagnostic socket
23 — a diagnostic control lamp
24 — the differential sensor of pressure
25 — the fuel pump

The electronic control system of the engine allows:

- To reduce the content of harmful substances in the fulfilled gases thanks to an exact task of the moment of ignition in any operating conditions of the engine.
- To increase ignition spark power on the petrol engine and therefore reliability of start and stability of its work.
- Self-diagnostics of a control system of the engine, provides possibility of fast troubleshooting. The control system of the engine has memory of malfunctions. If defect in use comes to light, it is brought in memory of the device. By means of special devices it is possible to output the list of malfunctions allowing to eliminate defect independently. Address also to the Section Diagnostics of Malfunctions. Work it is desirable to carry out HUNDRED in conditions.

The control unit of the engine represents the minicomputer with high speed. It, in addition, defines the optimum moment of ignition on the petrol engine, and on the diesel by means of the relay includes glow plugs. Thus there is a coordination of operation of the control unit with other systems of the car, for example, to a control system of a check point or blocking from stealing.

Elements of a control system of the engine keeps the high performance for a long time and practically does not demand service. Replacements, when carrying out maintenance, demand only a spark plug. Serious works on adjustment and repair demand use of difficult diagnostic units. Address to the Section Diagnostics of Malfunctions. Works it is desirable to carry out HUNDRED in conditions.
Correction of the moment of ignition on petrol engines, within carrying out maintenance, is not required.

Owing to good starting characteristics of the diesel engine with direct injection preliminary heat is required generally at temperatures below 0 °C.

Information arriving from various sensors, and the teams arriving to executive bodies ensure optimum functioning of the engine in any mode. If sensors fail, the monitor switches in emergency operation to exclude damages of the engine and to provide possibility of the further movement of the car. Failure of sensors not necessarily has to be felt on deterioration of operation of the engine.
However no later than the next review period of the fulfilled gases (AU) data on it will be brought in memory of malfunctions of a control system of the engine.

- The system of ignition has no mobile parts, the traditional distributor of ignition is absent. Each spark plug has the coil.
- The ignition tension monitoring system at too low voltage switches-off the DME block (for example, owing to damage of a cable). Thus the engine cannot be started. It excludes damages of the catalytic converter.
- The system of anti-detonation regulation serves for definition and regulation of optimum time of ignition for each cylinder. If there is a malfunction in system of ignition, supply of fuel to the corresponding cylinder stops.
- The relay of the fuel pump is in the relay block over a ware box. The relay gives current to the fuel pump.

General description of system of self-diagnostics of OBD

1 some diagnostic devices making monitoring of separate parameters of systems of decrease in toxicity and fixing the revealed refusals in memory of the onboard processor in the form of individual codes of malfunctions are a part of OBD system. The system makes also check of sensors and actuation mechanisms, controls vehicle service cycles, provides possibility of storing even the failures which are quickly arising in the course of work and cleaning of the block of memory.
2 All petrol models described in the present manual are equipped with system of onboard diagnostics of the second generation (OBD-II). A basic element of system is the onboard processor more often called by the electronic module of management (ESM), or the module of management of functioning of the power unit (RSM). RSM is a brain of a control system of the engine. Basic data arrive on the module from various information sensors and other electronic components (switches, the relay, etc.) . On the basis of the analysis of the data arriving from information sensors and according to the basic parameters put in memory of the processor, RSM develops commands for operation of various operating relays and actuation mechanisms, carrying out thereby adjustment of working parameters of the engine and providing maximum efficiency of its return at the minimum fuel consumption. Data read-out of memory of the OBD-II processor is made by means of the special scanner connected to the 16-contact diagnostic socket of reading of a database (DLC) located under the dashboard from the driver's party of the car or to the 20-contact socket located at the left in a motive compartment. Address to the section Diagnostics of Malfunctions.

In principle, reading of the codes of malfunctions which are written down in memory of system of self-diagnostics can be made by means of a lamp "Check the engine".

3 On service of components of control systems of engine/decrease in toxicity of the fulfilled gases special guarantee certificates with the extended validity extend. It is not necessary to make attempts of independent performance of problem diagnostics of RSM or replacement of components of system, to an exit of terms of these obligations, - address to specialists of firm car repair shops.

Information sensors

4 Oxygen sensors (l-probes) - the Sensor are developed by a signal which amplitude depends on a difference of the content of oxygen (O2) in the fulfilled gases of the engine and external air before and after the catalytic converter.

5 Sensor of provision of a cranked shaft (SKR) - The sensor informs RSM on the provision of a cranked shaft and turns of the engine. This information is used by the processor during the determining of the moments of injection of fuel and installation of a corner of an advancing of ignition.

6 Sensor of position of pistons (CYP) - On the basis of the analysis of the signals of RSM arriving from the sensor calculates position of the piston of the first cylinder and uses this information when determining the moments and sequence of injection of fuel in engine combustion chambers.
7 BMT (TDC) sensor - The signals developed by the sensor are used by RSM when determining installations of a corner of an advancing of ignition at the time of start of the engine.

8 The sensor of temperature of cooling liquid of the engine (eats) - on the basis of information of ECM/PCM arriving from the sensor carries out necessary corrections of composition of air and fuel mix and a corner of an advancing of ignition, and also controls work of EGR system.

9 The sensor of temperature of the soaked-up air (IAT) - RSM uses information arriving from the IAT sensor at corrections of a stream of fuel, installations of a corner of an advancing of ignition and management of functioning of EGR system.

10 Sensor of provision of a butterfly valve (TPS) - The sensor is located on the case of a throttle and connected to an axis of a butterfly valve. Determines a corner of opening of a butterfly valve (is operated by the driver from a gas pedal) by amplitude of the given-out TPS of a signal of RSM and as appropriate corrects supply of fuel to inlet ports of combustion chambers. Failure of the sensor, or weakening of its fastening leads to interruptions of injection and violations of stability of turns of idling.

11 The sensor of absolute pressure in the pipeline (MAR) - The sensor controls the depression depth variations in the inlet pipeline connected with changes of turns of a cranked shaft and load of the engine and will transform the received information to an amplitude signal. RSM uses information delivered by the MAR and IAT sensors at thin corrections of supply of fuel.
12 Barometric sensor of pressure - the Sensor develops the amplitude signal proportional to changes of atmospheric pressure which is used by RSM at determination of duration of the moments of injection of fuel. The sensor is built in the RSM module and to service in an individual order is not subject.

13 The detonation sensor - the Sensor reacts to change of level of the vibrations connected with detonations in the engine. On the basis of information of RSM arriving from the sensor carries out the corresponding correction of a corner of an advancing of ignition.

14 Sensor of speed of the movement of the car (VSS) - As appears from its name, the sensor informs the processor on the current speed of the movement of the car.

15 Sensor of size of opening of the EGR valve - The sensor notifies RSM on the size of shift of a plunger of the EGR valve. The received information is used then the processor at management of functioning of system of recirculation of the fulfilled gases.
16 Pressure sensor in a fuel tank - the Sensor is a component of system of catching of fuel evaporations (EVAP) and serves for tracking of pressure of vapors of gasoline in a tank. On the basis of information of RSM arriving from the sensor gives out commands for operation of electromagnetic valves of a purge of system.
17 Sensor switch of pressure of system of hydrostrengthening of a wheel (PSP) - On the basis of information of RSM arriving from the PSP sensor switch provides increase of turns of idling due to operation of the IAC sensor for the purpose of compensation of the increasing loads of the engine connected with functioning of the steering hydraulic booster at commission of maneuvers.
18 Transmission sensors - In addition to the data arriving from VSS, RSM receive also information from the sensors placed in a transmission, or connected to it. Are among such sensors: (a) sensor of turns of a secondary (radical) shaft and (b) sensor of turns of an intermediate shaft.
19 The sensor switch of management of turning on of the coupling of coupling of the conditioner of air - When giving power supply from the battery to the electromagnetic valve of the K/V compressor the corresponding information signal arrives on RSM which regards it as the evidence of increase of load of the engine and as appropriate corrects turns of its idling.
Actuation mechanisms
20 Main PGM-FI relay (relay of the fuel pump) - RSM makes activation of the relay of the fuel pump when turning the ignition key in the situation START or RUN. At ignition inclusion activation of the relay provides rise in pressure in a power supply system. More detailed information on the main relay is provided in the Head of the Power supply system, injection and release.
21 Injectors of fuel - RSM provides individual inclusion of each of injectors according to an established order of ignition. Besides, the module controls duration of opening of injectors determined by the width of the operating impulse measured in milliseconds and defining amount of the fuel injected into the cylinder. More detailed information on the principle of functioning of system of injection, replacement and service of injectors is provided in the Head of the Power supply system, injection and release.
22 Module of management of ignition (ICM) - The module operates functioning of the coil of ignition, defining the demanded basic advancing on the basis of the developed RSM of teams. On all models of cars considered in the present manual ICM which is built in the distributor of ignition is used, is more detailed in the present Chapter.

23 Valve of stabilization of turns of idling (IAC) - The IAC Valve carries out a dosage of amount of the air bypassed bypassing a butterfly valve when the last is closed or holds idling position. Opening of the valve and formation of the resulting air stream RSM operates.

24 Electromagnetic valve of a purge of a coal adsorber - the Valve is a component of system of catching of fuel evaporations (EVAP) and, working at the command of RSM, carries out production of the fuel vapors which accumulated in an adsorber in the inlet pipeline for the purpose of burning them in the course of normal functioning of the engine.
25 The electromagnet of management of a purge of a coal adsorber - the Electromagnet is used by RSM when checking by OBD-II system of serviceability of functioning of EVAP system.

Reading of codes of malfunctions

26 At detection of the malfunction repeating in a row on two trips, RSM gives out command for inclusion of the control lamp which is built in in an instrument guard "Check the engine", called also by the indicator of refusals. The lamp will continue to burn until memory of system of self-diagnostics is not cleared of the codes of the revealed malfunctions brought in it (address to Specifications). Reading of codes of malfunctions in OBD-II system can be made in various ways. The main way is reading by means of described in the Section Diagnostics of Malfunctions of Devices, connected to the 16-contact DLC socket of OBD-II system. Other ways are possible not on all models. The blinking code (determined by the producer and other than SAE standard codes "P") can be schitan on a lamp "Check the engine".


27 without starting the engine, include ignition, - a control lamp "Check the engine" has to light up, otherwise it should be replaced. Having checked serviceability of a condition of a lamp, again switch off ignition.

Method of reading of the blinking codes by a lamp "Check the engine" (it is possible on some models)

28 After ignition inclusion completely squeeze out five times within five seconds and release an accelerator pedal. If in memory of the processor codes of the malfunctions taking place are brought, they will start being highlighted consistently by a control lamp "Check the engine" on a control panel of the car. Consider the blinking code.

The lamp expects 5 sec., one flash follows, then the code with intervals of 2.5 sec. between categories is given. After delivery of a code a lamp it is necessary to burn. Repeat procedure to consider the subsequent codes. If the first given-out code 1444, 2444 or 4444 - malfunctions are not recorded.
The codes 1000 or 2000 which are given out by one or two flashes and a long pause, and then continuous burning of a lamp indicate the end of delivery of a code.

The blinking codes, differ from codes "R ", provided in Specifications.

Start of the engine automatically interrupts access to system of diagnostics.

Cleaning of memory of OBD-II

29 When entering a code of malfunction in memory of RSM on an instrument guard of the car the control lamp "Lights up check the engine". The code remains written down in memory of the module.
30 For cleaning of memory of ESM connect the scanner to system and choose the CLEARING COEDS function (Removal of codes) in its menu. Further follow the instructions highlighted on the device or at once for 30 seconds take from the nest in the assembly block EFI safety lock. Alternatively cleaning of memory of system can be made by removal of a fusible insert (the main safety lock of the system of onboard power supply) installed close the positive plug of the battery (see the Head Onboard electric equipment) (it is possible to disconnect also simply from the battery a positive wire).

It must be kept in mind that when cleaning memory of OBD by a detachment of a negative wire from the battery, adjusting parameters of the engine are erased and stability of its turns for a short time after primary start is broken.

If the stereosystem established on the car is equipped with a security code before disconnecting the battery, make sure that have the correct combination for input of the audio system in action!

Shutdown of the battery also leads to removal of settings of the receiver for favourite radio stations.

In order to avoid damage of ESM its shutdown and connection should be made only at the switched-off ignition!

31 Track that memory of system was cleared before installation on the engine of new components of systems of decrease in toxicity of the fulfilled gases. If before start of system after replacement of the failed information sensor not to make cleaning of memory of refusals, RSM will bring in it a new code of malfunction. Cleaning of memory allows the processor to make change-over on new parameters. Thus the first 50 - 20 minutes after primary start of the engine some violation of stability of its turns can take place.