7.2.1. Checks of serviceability of functioning of system of ignition

General information

All components of a power supply system differ in high degree of reliability. The majority of refusals, as a rule, are connected with violation of quality of contact connections of an electrical wiring. Breakdowns of VV of an electrical wiring most often happen owing to pollution, moistening or violation of integrity of isolation. Before finally being approved in opinion on failure any of system components attentively check a condition of an electrical wiring of the corresponding contour.

Authors of the present manual do not recommend to carry out check of a condition of VV of conducting in such popular way as a detachment of wires from candles and approach of a terminal tip to the surface of the block, - such procedure is fraught not only receiving an electric trauma, but failure of the module of management or the coil of ignition. At violation of stability of turns of the engine do not disconnect wire VV from candles!

The checks given below should be carried out at obvious violations, such as refusal of a starter or emergence of admissions of ignition. Some malfunctions are not so obvious and can not be shown in view of automatic transition of a control system to emergency operation of functioning at all. Refusals of this sort have usually an effect only in the indirect way (on increase in fuel consumption, violation of stability of turns of idling, decrease in the power developed by the engine, etc.), - address for consultations specialists of car service.

The engine is not started

The refusal of start of the engine can be a consequence of failure of an immobilizator of anticreeping system, - switch-off the alarm system and system of an immobilization (see the Head Governing bodies and methods of operation).


  1. If the engine is not turned at inclusion of a starter or turned very slowly, check a starter and the rechargeable battery. Connect the voltmeter to plugs of the battery and measure tension at a provorachivaniye of a bent shaft by a starter.

Do not include a starter continuously more, than for 10 seconds.

  1. If the voltmeter registers the indication in 9.5 B and below, check serviceability of a condition of the battery, a starter and components of system of a charge (see the Part of System of a charge and start of the present Chapter).
  2. If the engine is not started despite serviceability of a provorachivaniye it by a starter, check a condition of all VV of a contour of system of ignition.
  3. Following instructions of manufacturers, connect a stroboscope and turn the engine a starter, - if the lamp on a stroboscope lights up, therefore, tension regularly is given for spark plugs. Check serviceability of a condition of candles (see the Head Nastroyki and routine maintenance of the car). If the lamp does not light up, check a condition of VV of an electrical wiring (see the Head Nastroyki and routine maintenance of the car).
  4. At violation of serviceability of sparking check a condition of the coil/module of ignition by replacement it on obviously serviceable, or check of resistance of windings. If after replacement of the coil/module the engine began to be started, do not hurry to throw out the old coil, - before a condition of its contact plugs and reliability of connection of an electrical wiring to them.
  5. If the coil as it should be, perhaps a cause of failure is covered in violation of serviceability of functioning of ECM of the powerful buffer output cascade, one of information sensors of a control system of the engine which is a part, or any accompanying knot. In a similar situation in the processor memory of ECM the corresponding diagnostic code is usually brought, - reading of codes of malfunctions is made by means of the special diagnostic equipment (see the Head Sistemy of electric equipment of the engine).

Admissions of ignition

Violation of quality of terminal connections of an electrical wiring of the coil/module of ignition or any of information sensors appears the reason of admissions of ignition most often.


  1. Switch off ignition and check reliability of fixing of all contact sockets of system of ignition.
  2. Check a condition of VV of an electrical wiring, - estimate reliability of fixing of candle wires in intermediate clamps, make sure that wires do not concern metal parts of the power unit. If the wire concerns metal and it damaged isolation, then during the operation of the engine the spark will move not on a candle, and on weight. At detection of signs even of insignificant damage of isolation at least of one wire replace all set.
  3. The most reliable way of check is replacement of a set of a candle electrical wiring on obviously serviceable.
  4. You make replacement of wires serially in order to avoid violation of an order of ignition. Try not to allow damages of isolation or the socket.
  5. If VV conducting is serviceable, the failure of the coil/module or any of spark plugs can be the reason of admissions of ignition. Change candles (see the Head Nastroyki and routine maintenance of the car). Can lead to admissions of ignition also failure or pollution of the sensor of provision of a bent shaft (see the Head of the Power supply system, release and decrease in toxicity of the fulfilled gases). If during the checks conducted independently it is not possible to establish a cause of infringement, the car should be driven away on car repair shop for performance of full diagnostics of a control system with use of the special equipment (see the Sections System of Onboard Self-diagnostics of OBD - the general information and Application of an oscillograph for observation of working parameters of a control system).