Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car

Audi 80/Avant
+ Technical specification
+ Engines
+ System of production of the fulfilled gases
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
+ System of injection
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
- System of ignition
   Various systems of ignition
   Principle of work of ignition
   Executive body
   "Brain" of system
   Impulses for the control unit
   Regulation on a detonation
   Security measures during the work with system of ignition
   Repair of system of ignition
   Diagnostics of system of ignition
   Ignition distributor
   Sensor of detonation combustion
   Elements of a high voltage
   Replacement of spark plugs
   Spark plugs
   Check of the moment of ignition
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications

"Brain" of system

Under a covering (shooter) sideways at feet of the forward passenger on models with the 5-cylinder engine the control unit (2) of completely electronic system of ignition is located. Also here the sensor of pressure of external air (1) system of injection of KE-III-Jetronic is placed.

Control unit

At the majority of engines management of ignition of system is executed integrated with management of injection of system. The exception is made only by models with the 5-cylinder engine: here at each system (ignition and injection) the own control unit. But on a way of action there are no distinctions. The small list of that does the control unit is lower.

  • Systems of ignition of Audi cars do not need the additional device for regulation of the moment of ignition. Various data and indicators of the engine are at the disposal of the control unit. Their receipt is provided with the sensor of the Hall or the sensor of number of turns of the engine and the provision of a cranked shaft, and also sensors of temperature of the engine, the provision of a butterfly valve, etc. According to all these data the control unit counts the ignition moment, right for the corresponding condition of loading.
    If to represent an ignition advancing corner (the ignition moment) depending on loading and number of turns of the engine, we will receive the so-called characteristic of ignition. The characteristic of new systems of ignition is represented willingly because of its freakish form – on it it is possible to make the conclusion about exact impact on the operational modes.
  • Adjustment programs, somehow are at the disposal of the control unit: for start of the engine, operation of not heated-up engine, the movement in the mode of compulsory idling etc.
  • The control unit allows to the ignition coil always exactly so much current, how many for it it is necessary time at present. In an extreme situation (the included ignition, but the idle engine) these systems of ignition even after a long time can have no damage of the coil of ignition.
  • Regulation on a detonation (except model with the 66 kW engine) gives the chance to operate the engine with the most exact advancing of ignition and consequently, with the highest power. Therefore the engine designed for work on AI-95 gasoline (super), can work and at AI-92 gasoline as the control unit distinguishes lower octane number and switches to the mode of later ignition.
  • Besides, there is a data exchange to system of injection. As some sensors on the engine are used twice. This process is carried out even on models with the 5-cylinder engine though here systems of ignition and injection are supplied with different control units (KE-III-Jetronic and VEZ).

  • And, at last, the store of malfunctions which is writing down defects of system of ignition which memory can be interrogated in a workshop by the special device is installed (see also section Regular servicing).