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Troubleshooting - general information and preliminary checks

Refer also to Section Diagnostics of malfunctions.

Ignition systems and power are interrelated components of the engine management system, so some of its components can also perform functions related to the supply system.

general information

Ignition systems and power have a common diagnostic system designed to save the trouble code (DTC) and diagnosis. In identifying the failure of the control unit stores the corresponding code DTC, which can be read with a special scanner.

Reading of information stored in the memory of ECM, in most cases to determine the causes of malfunctions of the engine. Analysis of the read information with the code list (see. Specifications) allows you to locate the source of failure at the level of a particular element, or its electrical circuit.

Visual inspection of wiring and connectors is not enough - must consider the information stored in the memory of the control unit!

Preliminary checks

If the problem occurred shortly after the service of a node, first of all, it should be carefully examine the unit and located adjacent components - it is possible that the cause of the failure is related to the violation of the basic quality of contact connection.

When searching for the reasons of infringement of serviceability of functioning of the engine (for example, the drop developed capacity) always makes sense to check the cylinder compressions (see. Chapter Engine). Also ensure that the replacement of the air and fuel filters made in accordance with the maintenance schedule (see chap. Adjustment and car routine maintenance).

Do not forget to clean the memory of the control unit after reading fault codes and make the appropriate corrections.

PERFORMANCE ORDER

Open the hood and check the reliability of fixing of tips of wires on the pole terminals of the battery, make sure that there are no signs of oxidation of terminal connections. If necessary, make appropriate measures to deal with problems, defective components replace. No less carefully examine the tires and the ground terminal connections - contact surface of the respective elements of supply (power unit / body panels) must be completely clean and free of corrosion. Carefully inspect all visible electrical wiring inside the engine compartment, check the contact connections. With pronounced signs of damage, replace the wiring harness, making sure wiring harness; if necessary tighten fasteners unnerved nodes on which frayed insulation. Risk area are always areas wiring passing near serviceable parts are produced in the most recent time. It should be remembered that the electrical conductors may be damaged with no signs of damage to the insulation - in this situation, the external examination will not give positive results. Such injuries can result from pulling the wires, or in violation of their routes pads. Restore the wiring can be damaged by soldering on the site break bridging veins - ration provides a reliable electrical contact. To repair the insulation, use insulating tape or set him on the wire cut heat shrink tubing. The best (though not the cheapest) way to eliminate all associated with damage to the electrical failure is the replacement of faulty wires. After finishing the refurbishment / replacement of picking, track correctness pads associated wiring, paying particular attention to portions of routes warmed up near the surface and moving parts in the engine compartment. Track reliability of fixing harnesses all provided intermediate clamps. Check all terminal connections are available, check the mounting pin connector wiring. If any connector on the inner surface corrosion (white or green deposits, rust), and the excessive contamination, remove the connector with appropriate terminals and clean them, if necessary, by using a special spray. Seriously damaged connectors must be replaced, in some cases, complete with cable harness. After cleaning connector corrosion tamp it before reinstalling the preservative grease. On considered in this manual car uses the crankshaft position sensor (CKP), which measures the TDC position of first cylinder. Excessive dirt or dust sensor can cause misfiring. Inspect hoses and tubes of all vacuum lines the engine compartment. Check tightening of fixing clamps, make sure there is no deformation, cracks, cuts, bundles, and other physical damage of hoses and tubes. Carefully read choke assemblies for signs of leakage (see chap. Adjustment and car routine maintenance). Assess and cross-check the hoses PCV. Excessive pollution or violation of internal hose entails infringement of stability of turns of the engine, especially at idle. Moving from the fuel tank to the fuel distribution manifold (through the fuel filter) along the fuel lines, carefully examine the condition of the fuel lines. Pay special attention to places of articulation tubes, where most cracks through which begin to develop leaks. Damaged sections replace fuel lines. Check the condition of the air filter element. Excessively dirty filter can significantly increase the total aerodynamic resistance of the air intake tract, which directly affects the power developed by the engine. If necessary, replace the filter element. Start the engine and leave it running at idle. When performing any work in the engine compartment with the engine running, observe extreme caution - be careful not to touch the heated surfaces of the power unit and exhaust system, do not expose the hair and items of clothing in the moving parts (cooling fan, accessory drive belt) ! Moving from the air intake to the air cleaner and beyond - to the throttle body, make sure that there are no signs of development of leaks of air in the intake tract. To identify sources of leaks you can use soap and water. Make the necessary corrections. Drive the vehicle on a lift and examine the state of the components of the exhaust system. Make sure there are no signs of leaks, - the easiest way to detect leakage of the exhaust tract is possible by plugging its outlet - the characteristic whistles and smoke to help locate the damaged area. Pull weakened collars / replace defective gaskets, replace the damaged section. The final stage of testing with the engine running alternately tug of its electrical connectors - the poor quality of contact will indicate the changing nature of the engine - make the necessary corrections, replace the failed portions of the wiring. If in the course of preliminary checks to identify the cause of instability of the engine fails, the car should be driven away to the service station to carry out a more thorough diagnosis using special equipment.