Mercedes M-Class W163

since 1997 of release

Repair and car operation

Checks of a control system by ignition and injection

See also Section Diagnostics of malfunctions in Introduction at the beginning of the Management.

General information

Components of systems of ignition/management of the engine are among elements of increased reliability and the majority of refusals, as a rule, appear connected with violation of quality of contact connections or electroconducting damage. Breakdowns of VV of electroconducting occur in a consequence of pollution, moistening or isolation damage more often. Before coming to conclusion about failure of a component of system, always first of all check a condition of the corresponding electroconducting and its contact connections.

Do not make check of serviceability of giving of tension on spark plugs by a detachment from them of electroconducting and its approbation on mass of the engine, - such diagnostics is interfaced not only to risk receiving an electroshock, but also with danger of failure of ECM or the ignition coil. At violation of stability of working turns of the engine also it is not necessary to make identification of the faulty cylinder by a consecutive detachment of electroconducting from spark plugs.

Listed below check allow to define the reason of the malfunctions which symptoms are rather obvious (starter refusal, ignition admissions, etc.). Some, less obvious, violations can not show themselves at the expense of automatic transition of a control system to emergency operation of functioning and are shown only in fuel consumption increase, violation of stability of turns of idling, to reduction of efficiency of return of the engine, emergence of detonations and so forth, - address for consultations to specialists of car-care center.

The engine is not started

Remember that at failure of the anti-theft device start of the engine is not obviously possible, - disconnect an immobilizer (see. Head Governing bodies and operation receptions).

PERFORMANCE ORDER

If the starter does not turn the engine, or rotates it too slowly, first of all check serviceability of functioning actually a starter, and also a condition of the storage battery. Connect the voltmeter to plugs of the battery and measure its target tension at an engine provorachivaniye by a starter. If the result of measurement makes less than 9.5 In, it is necessary to check serviceability of a condition of the battery, a starter and components of system of a charge. Do not activate a starter continuously more than within 10 seconds! If the engine is not started despite serviceability of rotation of a starter, check a condition of all VV components of a contour of system of ignition. Operating strictly according to instructions of the manufacturer, connect a stroboscope and turn the engine a starter, - activation of a lamp of a stroboscope confirms serviceability of giving of VV of tension on spark plugs. Check a condition actually candles. If the stroboscope does not work, estimate a condition of VV of electroconducting (at the corresponding complete set, - see. Head Current leaving and service). At a serviceable iskroobrazovaniye act according to the recommendations provided in the Section Check and adjustment of a corner of an advancing of ignition. In the absence of an iskroobrazovaniye make sure of serviceability of the coil (ек) ignitions (simplest to replace the coil obviously serviceable, - alternatively to measure resistance of windings). Do not hurry to throw out the coil suspected of refusal, - before make sure of quality and reliability of its contact connections. Violation in the powerful buffer target cascade being a component of the module of management of the engine (ECM), and also malfunction any of information sensors of a control system, or other accompanying knot can be one more cause of failure of start of the engine, - check memory of ECM on existence of the diagnostic codes (DTC) written down in it. Reading of the DTC codes is made by means of the special diagnostic equipment (see. Diagnostics of systems of electronic control and diagnostic equipment).

Ignition admissions

PERFORMANCE ORDER

The reason of admissions of ignition is violation of quality of contact connections of electroconducting on plugs of coils of ignition or any of information sensors more often. Switch off ignition and check the corresponding contact sockets on existence of signs of oxidation and reliability of fixing on plugs. At the corresponding complete set believe a condition of VV of electroconducting. Make sure of reliability of fixing of wires in all provided intermediate clamps, be convinced that wires do not adjoin to metal parts of the engine, - if the wire with the broken isolation concerns some metal, at operation of the engine the iskroobrazovaniye will take place not between contacts of the corresponding spark plug, and in a breakdown place. At identification even insignificant damage of isolation at least one wire replace all set. To make sure of serviceability of a condition of VV of electroconducting it is simplest by replacement of all set on obviously serviceable. In order to avoid risk of violation of correctness of connection, replacement of candle wires make serially. At serviceable electroconducting by the reason of admissions of ignition failure actually candles, or bobbin assembly can be, - replace candles (see. Head of the Power supply system and production of the fulfilled gases), check a coil condition. Damage or pollution of the sensor of position of the crankshaft (CKP) can be the reason of emergence of admissions of ignition also. If performance listed above checks does not allow to reveal a cause of infringement, make reading of the DTC codes from memory of the module of onboard self-diagnostics (ECM).