Audi A4, S4

Since 2000 of release

Repair and car operation

Audi A4, S4
+ Introduction
+ Controls and receptions of safe operation
+ Current leaving and service
+ The engine
+ Systems of cooling, heating and the air conditioner
+ Power supply systems, release and decrease in toxicity of the fulfilled gases
- Systems of an electric equipment of the engine
   - Ignition and engine management system
      The basic data and security measures
      Checks of a control system by ignition and injection
      Search of malfunctions - the general information and preliminary checks
      Check and adjustment of a corner of an advancing of ignition
      Spark plugs
   + System of preheat of the diesel engine
   + Diagnostics of systems of electronic control and the diagnostic equipment
   + Gymnastics and start systems
+ Manual box of a gear change
+ Automatic transmission
+ Coupling, power shafts and differential
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

Checks of a control system by ignition and injection

Address also to Section Diagnostics of malfunctions.

Control system components are very reliable. Malfunctions, as a rule, are connected with unreliability or pollution of contacts. Breakdowns of high-voltage wires arise because of pollution, humidity or isolation damage, instead of because of malfunction a system component more often. Before drawing a conclusion on malfunction of any component, check up its conducting.

To check working capacity of a high-voltage wire, having removed it from a candle and having approached to an engine surface (observing of spark presence), it is impossible. You risk not only to receive blow by a current, but also to damage the block of management or the ignition coil. If the engine works astably, never remove tips of wires from candles for definition of the faulty.

Described below check it is necessary to carry out, if malfunction is obvious (starter refusal, admissions of ignition, etc.). Some malfunctions are less obvious and can not be shown that the control system of the engine was switched in the emergency operation ignoring signals of separate gauges and using. This sort of malfunctions are shown in increase of the expense of fuel, instability of turns of idling, loss of capacity, a detonation etc. If you have found out similar symptoms, address on HUNDRED.

The engine is not started

Keep in mind that at failure of the antijoy ride device you cannot start the engine. Disconnect the device (address to the Head Controls and receptions of safe operation).

If the engine is not turned at inclusion of a starter or turned very slowly, check up a starter and the storage battery. Attach the voltmeter to plugs of the battery and measure pressure at проворачивании коленвала the engine by a starter. Do not include a starter more than for 10 seconds. If the voltmeter shows 9.5 Volt and less, be convinced of serviceability of the accumulator, a starter and gymnastics system (address to Section of System of a gymnastics and start).

If at inclusion of a starter the engine rotates with usual speed, but is not started, check up all high-voltage components of system of ignition.

Following instructions of the manufacturer, connect a stroboscope and turn коленвал the engine a starter. If the lamp on a stroboscope lights up, pressure arrives on spark plugs. Be convinced of serviceability of candles. If the lamp is not lighted, check up high-voltage wires (address to Section Check and replacement of spark plugs. Check of a condition of high-voltage wires).

If the spark is not present, be convinced of serviceability of the coil of ignition (or replace the coil on obviously serviceable or check up resistance of windings). If malfunction is not found out, search for it in other place. If after replacement of the coil the engine has started to be started — malfunction is found out. Do not hasten to throw out the coil and to buy the new. Be convinced of reliability of joining of conducting to the coil (the engine could not be started because of the oxidised contact).

If the coil is perfectly in order, is faulty, probably, powerful buffer target cascade which is a component of the block of management of the engine, one of gauges of a control system of the engine or the accompanying knot. In this case in memory of the block of management the code of malfunction as which it is possible to consider from memory should be written down.

It is possible to consider codes of malfunctions by means of the special equipment.

Ignition admissions

The reason of admissions of ignition is unreliable contact of conducting to plugs of the coil of ignition or any gauge more often.

Switch off ignition and be convinced of reliability of joining of all sockets of system of ignition.

Check up high-voltage wires. Be convinced that they are reliably fixed in points промежуточныхкреплений and do not adjoin to metal parts of the engine. If the wire concerns metal and at it isolation at work of the engine the spark will be submitted not on a candle, and on weight is damaged. At detection even insignificant damage of isolation at least one wire replace all complete set.

To be convinced of full working capacity of wires it is possible, temporarily having replaced them on obviously serviceable.

At replacement of wires change them on one. It you will avoid risk of wrong connection. Do not damage a wire at installation.

If high-voltage wires are completely serviceable, the reason of occurrence of admissions of ignition is, most likely, the coil of ignition or any spark plug. Establish the new complete set of candles (address to Section Check and replacement of spark plugs. Check of a condition of high-voltage wires) or check up the coil. The faulty or dirty gauge of position коленвала (address to Section Functioning of a control system and injection of the petrol engine) can be the reason of occurrence of admissions of ignition.

If check of aforementioned knots has not led to improvement of work of the engine, consider codes of malfunctions from memory of the block of management (address to Section the Controller of interface of the personal computer with onboard system of self-diagnostics OBD II under reports of standards SAE (PWM and VPW) and ISO 9141-2 and to Specifications).