Saab 9-5

Since 1997 of release

Repair and car operation

Search of malfunctions - the general information and preliminary checks

Ignition and food systems are the interconnected components of a control system of the engine, therefore some of its components can carry out also the certain functions concerning functioning of the power supply system.

The general information

Ignition and food systems have the general diagnostic system intended for preservation of codes of malfunctions (DTC) and carrying out of diagnostics. At revealing of refusal the management block writes down the corresponding code DTC representing some sequence of signals which can be считана by means of the special scanner in memory of the processor.

Reading of the information stored in memory ECM, in most cases allows to define the reasons of failures in work of the engine of the car. The analysis считанной information with application of the list of codes (Specifications see) allows to localise a refusal source at level of a concrete element, or a chain of its electroconducting.

Preliminary checks

If malfunction has arisen soon after performance of service of any knot, first of all, it is necessary to investigate carefully the given knot and the components located in the neighbourhood, - is not excluded that the cause of a failure is connected with elementary infringement of quality of contact connection.

By search of causes of infringement of serviceability of functioning of the engine (for example, falling of developed capacity) always makes sense to check up a compression in cylinders. Watch also that replacement of air and fuel filters was made according to the maintenance service schedule (see the Head of Adjustment and car routine maintenance).

Do not forget to clear memory of the block of management after reading of codes of malfunctions and entering of corresponding corrections.

Open a cowl and check up reliability of fixing of tips of wires on polar plugs of the battery, make sure of absence of signs of oxidation клеммных connections. In case of need make corresponding measures on the debugging, the failed components replace. Not less attentively study a condition of tyres of grounding and them клеммных connections, - contact surfaces of corresponding elements of weight (the power unit/kuzovnye of the panel) should be absolutely pure and free from corrosion traces.

Attentively examine all visible electroconducting in an impellent compartment, check up reliability of contact connections. Having strongly pronounced signs of damage electroconducting replace, having tracked correctness of a lining of plaits; in case of need tighten ослабший fixture of knots about which isolation has frayed.

It is necessary to remember that current-carrying veins of electroconducting can appear damaged in the absence of signs of damage of isolation, - in a similar situation external survey will not give positive results. Similar damages can result вытягивания from wires, or at infringement of routes of their lining.

To restore the damaged electroconducting it is possible a way впаивания on a site of breakage of a shunting vein, - the soldering provides reliability of electric contact. For isolation repair take advantage изоляционной of a tape, or plant on a wire a piece of a thermoshrinkable tube. The best (though and not to the cheapest) way of elimination of all interfaced to damage of electroconducting of refusals is replacement of the failed wire.

Having finished regenerative repair/having picked up replacement, track correctness of a lining of corresponding plaits, special attention giving to the sites of routes which are passing near to warmed up surfaces and moving components in an impellent compartment. Track reliability of fastening of plaits in all provided intermediate clamps.

Check up a condition of all accessible клеммных connections, check up reliability of fastening of contact sockets of electroconducting. At revealing on an internal surface of a socket of traces of corrosion (white or green adjournment, a rust touch), and also at excessive pollution, remove a socket from the corresponding plug and carefully clear, in case of need having taken advantage of a special spray. Seriously damaged sockets are subject to replacement, in certain cases in the complete set with an electroconducting plait.

After clearing of a socket of corrosion traces fill it before installation to the place of preserving greasing.

On cars considered in the present Management the inductive gauge of position of a cranked shaft (CKP) with which help position ВМТ of the piston of the first cylinder is defined is used. Excessive pollution or запыление the gauge can be at the bottom of ignition admissions.

Attentively examine hoses and tubes of all vacuum lines of an impellent compartment. Check up reliability of a tightening of fixing collars, make sure of absence of deformations, cracks, cuts, stratifications and other physical damages of hoses and tubes. Attentively study штуцерные knots on presence of signs of infringement of tightness. It is necessary to give special attention to a condition of the lines laid near to keen edges. Depression losses are usually accompanied by characteristic whistle at which revealing it is necessary to grease a suspected site of a hose with a soap solution, - it is possible to consider a leak source found out if at drawing of a solution stability of turns of the engine raises. Tighten ослабшие collars, replace the damaged lines.

Estimate a condition and check up passableness of hoses of system PCV (see the Head of the Power supply system and release of the fulfilled gases). Excessive pollution or infringement of passableness of hoses involves infringement of stability of turns of the engine, especially idling.

Moving from a fuel tank to a fuel distributive highway (through the fuel filter) along fuel pipelines, attentively study a condition of fuel lines. Special attention give to places of a joint of tubes where cracks through which leaks start to develop more often are formed. The damaged sections of fuel lines replace.

Uncover an air cleaner and check up a condition of a filtering element. Excessively polluted filter is capable to raise considerably total aerodynamic resistance of an inlet air path that directly affects capacity developed by the engine. In case of need replace filtering element.

Start the engine and leave its working on single turns.

Moving from an air inlet to an air cleaner and further - to the throttle case, make sure of absence of signs of development of leaks of air in an inlet path. For revealing of sources of leaks it is possible to take advantage of a soap solution again. Make necessary corrections.

Tyre out the car on the lift and study a condition of components of system of release ОГ. Make sure of absence of signs of development of leaks, - is most easier to reveal thinnesses of a final path it is possible a way закупоривания its exhaust outlet, - characteristic whistle and smoke blanketing will help to localise the damaged site. Tighten ослабшие collars/replace the failed sealing linings, replace the damaged sections.

At the check final stage at the working engine serially pull contact sockets of its electroconducting, - change of a kind of work of the engine will testify to bad quality of contact, - make necessary corrections, replace the failed sites of electroconducting.

If during carrying out of preliminary checks to identify a cause of infringement of stability of work of the engine it is not possible, the car should be driven away on HUNDRED for performance of more careful diagnostics with application of the special equipment.