7.1.3. Search of malfunctions - the general information and preliminary checks

Oscillograms of signals of management of ignition

Address also the Section Application of an Oscillograph for observation of signals in chains of control systems.
1 — a CKA crankshaft Angle of rotation
2 — Number of the cylinder
3 — the Signal of the L5 CKP sensor of position of the crankshaft

4 — the Signal of the sensor of Hall of B6/1 of provision of a cam-shaft
5 — the Signal of turns of the TNA engine

Function chart of system of microprocessor control of V6 and V8 ME SFI 2.0 engines

50 — the Compressor
55 — the Fuel filter
55/2 — the Regulator of pressure of fuel of 5.0 bars
55/3 — the Regulator of pressure of fuel of 5.3 bars
55/3a — the Gate
55/4 — the spraying Camera
71 — the Control valve
75 — the Fuel tank
76 — the Ventilating valve
77 — the Coal adsorber
77/1 — Ventilation
89 — the EGR Valve
95 — the mix pumping Pump
110/2 — the Cooler of the forced air
110/10 — the Low-temperature cooler
110/11 — Additional low-distemper-turny a cooler
126/1 — the Left valve of shutdown of admixture of secondary air
126/2 — the Right valve of shutdown of admixture of secondary air
128 — the Retaining vacuum valve
157 — the Three-functional catalytic converter at a partition of a motive compartment
158 — the Three-functional catalytic converter under the bottom
A1 — the Control panel
A1e58 — the Control lamp of failure diagnostics of the engine
A16/1 — the Sensor of a detonation 1 (the right side of the engine)
A16/2 — the Sensor of a detonation 2 (the left side of the engine)
B4 — the Fuel level sensor
B4/7 — the fuel pressure Sensor
B6/1 — the Sensor of effect of Hall of the camshaft
B11/4 — the Sensor of temperature of cooling liquid (CTS)
B17/8 — the Sensor of temperature of the forced air
B28/8 — the Sensor of pressure of the forced air 1
B37 — the Sensor of provision of a pedal of an accelerator
B40 — the Sensor of level/temperature/quality of oil
B40/2 — the Sensor of pressure of oil of system of shutdown of cylinders 1
CAN "B" — the Tire of data in salon
CAN "C" — the Tire of data in a motive compartment
G2 — the Generator
G3/3 — Left dokataliticheskiya a lambda probe
G3/4 — Right dokataliticheskiya a lambda probe
G3/5 — Left post-catalytic a lambda probe
G3/6 — Right post-catalytic a lambda probe
K40/5kt — the Relay of the fuel pump
K40/7kL — the starter Relay
K40/7kN — the Relay of system of admixture of secondary air
K40/8kW — the Relay of the forced air

K40/8kX — the Relay of the fuel pump which is built in a tank
L5 — the Sensor of provision of a bent shaft (CKP)
L6/1 — the Sensor of the left forward wheel
L6/2 — the Sensor of the right forward wheel
L6/3 — the Sensor of the left back wheel
L6/4 — the Sensor of the right back wheel
M1 — the Starter
M3 — the Fuel pump
M3/1 — the Pump which is built in the fuel tank
M4/7 — the Electric fan of the engine and KV with the built-in control unit
M16/6 — the Activator of a butterfly valve
M16/7 — the Drive of the gate of recirculation air
M33 — the Electric air pump
M44 — the Circulation pulser of a cooler of the forced air
N2/7 — the Control unit of the limiting systems
N3/10 — the Module of management of injection of fuel (ME-SFI)
N15/3 — the Module of management of the electronic traction control system (ETC)
N15/5 — the AT selector lever Control unit
N22 — the Module of management of the press button of a control system of additional air (AAS)
N47-1 — the Module of management of the control system of thirst (ASR)/sensitive for the speed of system of hydrostrengthening of a wheel (SPS)
N47-5 — the Control unit of stabilization (ESP), SPS and the amplifier of brakes (BAS)
N73 — the Control unit of the electronic ignition key (EIS [EZS])
N80 — the Block of a steering column
N118 — the Control unit of the fuel pump
S9/1 — the Sensor switch of stoplights
S40/4 — the Variatorny switch of a tempostat
T1/1 - T1/8 — Dual coils of ignition of cylinders 1-8
X11/4 — the Diagnostic DLC socket
Y2/1 — Э / the magnetic coupling of the supercharger of the blown air
Y32 — the Valve switch of the air pump of system of admixture of secondary air (AIR)
Y58/1 — the Valve of management of an adsorber purge
Y62 — Injectors of fuel (LH-SFI, HFM-SFI, PEC [LH, HFM, PMS])

1 Only the engine 113.960 with system of shutdown of cylinders (code 479)

Connection of sockets of coils of ignition

5/1 — Tips of VV of wires
T1/1-T1/6 — Dual coils of ignition of cylinders 1-6
3-contact socket
1 — the Chain 1b

2 — the Chain 15
3 — the Chain 1a
and and b — VV - connections

Scheme of connections of coils of ignition

R4 — Candles
N 3/10 — the Control unit

L1 — Primary windings
L2 — Secondary windings

Address also the Section Diagnostics of Malfunctions of Introduction and the following Sections Self-diagnostics of Systems of Electronic Control of the Second Generation of OBD II, Controller of Interface of the Personal Computer with onboard system of self-diagnostics of OBD II under protocols of the SAE standards (PWM and VPW) and ISO 9141-2.

The system of ignition and fuel system are the interconnected components of a control system of the engine. In spite of the fact that in this Chapter only the system of ignition is considered, some from its component perform several functions concerning functioning of fuel system.

General information

The system of ignition and fuel system have the general diagnostic system intended for preservation of codes of malfunctions and performing diagnostics. At malfunction emergence the control unit writes down some sequence of signals (a malfunction code) which can be considered the special device subsequently in memory (address the Section Self-diagnostics of Systems of Electronic Control of the Second Generation of OBD II in which the description of the procedure of check of fuel system is provided).

If failures in operation of the engine of the car are observed, the reason of it, most likely, can be found out, having investigated memory of the control unit. After reading of codes of malfunctions it is possible to find out what knot is faulty and to execute the corresponding checks (either the knot, or its electrical wiring).

Visual check of an electrical wiring and sockets is not enough — surely consider information which is stored in memory of the control unit.

Preliminary checks

If malfunction arose soon after service of any knot, first of all carefully check this knot and surrounding space. Perhaps, the reason is covered in carelessly installed component or unreliably attached socket.

If you try to find the reason of a certain malfunction of the engine, for example falling of power, in addition to the actions given below measure a compression in cylinders. Make sure that the fuel filter and the air cleaner changed according to the ordered intervals.

Keep in mind that after reading of codes of malfunctions they need to be removed from memory of the control unit by means of the same diagnostic scanner then to eliminate malfunction.


1. Open a cowl and be convinced of reliability of accession of tips of wires to plugs of the accumulator and lack of corrosion on them. At detection of traces of corrosion or damages replace or clear wires. Similarly check all tires of grounding, having convinced that they provide reliable contact (the interfaced surfaces have to be absolutely pure and without corrosion traces) with a body or the engine.
2. After that attentively examine all visible conducting laid in a motive compartment. Be convinced of reliability of all connections. At this stage you are interested in obviously damaged wires. They can be cut or ground about the sharp or moving engine knots, for example, of a detail of a suspension bracket or a driving belt. The break of a wire can result from negligent installation of any knot. The wire can melt at contact with system of release. The wrong laying of its plaits in a motive compartment after performance of repair or service of any knot is the most probable cause of damage of conducting.
3. Wires can be damaged or short-circuited without damage of their isolation. In this case survey will not lead to anything. Similar damages can arise after a pulling of wires or the wrong placement of conducting in a motive compartment. If you consider that similar damage is possible, check a wire, following the sequence stated below.
4. The damaged wire can be repaired, having sealed a piece of a new wire in a gap. The soldering is necessary for receiving reliable contact. Isolation can be restored enough an insulating tape or a thermoshrinkable tube. If damages are considerable and the damaged wire plays an essential role, the most right exit (though) replacement of the corresponding plait on new will be rather expensive.
5. After restoration of the damaged wire correctly arrange it in a motive compartment, far from the rotating and hot knots. Do not forget to fix a wire in intermediate clamps (if is).
6. Be convinced of reliability and purity of all available sockets. All clamps have to be established. If on the internal surface of the socket you cover up corrosion tracks (white or green deposits, and also rust traces) or excessive pollution, remove it from the corresponding plug and carefully clear. For this purpose you can use special spray. If the socket is seriously damaged, it should be replaced. Keep in mind that in certain cases you should replace a plait entirely.
7. If you could remove completely corrosion traces from the socket, fill it with the preserving lubricant then establish into place. You can learn lubricant type on HUNDRED.
8. On all models the sensor of position of the crankshaft is installed (also VMT of the first cylinder decides on its help). Its working part can be polluted by oil or dust that can lead to failures in its work and, respectively, to admissions of ignition.
9. Attentively examine all vacuum hoses and tubes located in a motive compartment. Be convinced of reliability of an inhaling of collars and lack of cracks, stratifications and traces of damages on hoses. Be convinced also that no hoses not of a peredavlena and are bent too strongly, i.e. do not pass air. Pay special attention to the hoses located near keen edges and also the ends of all hoses. All damaged hoses need to be replaced.
10. Be convinced of lack of traces of damages and pollution on hoses of system of ventilation of a case. Be convinced also that they are not blocked from within. The quantity and installation sites of hoses of system depends on car model, but on all models the hose connecting the top part of the engine to a hose an air inlet or the inlet pipeline is established. Hoses of system connect also the block of cylinders (or a maslozalivny mouth) to the inlet pipeline. These hoses deliver oil vapors in combustion chambers. At pollution or blocking of these hoses the engine will unstably work (especially at single turns).
11. Following from the fuel tank via the fuel filter to the fuel distributive highway along fuel pipelines, attentively examine them. At detection of traces of damages or excesses replace the corresponding section. Pay special attention to junctions of tubes. On them there can be cracks leading to fuel leak.
12. Uncover the case of the air cleaner and examine an element. It has to be rather pure and dry. Strongly polluted cleaner shows strong resistance to an air stream that leads to noticeable deceleration of power of the engine. Replace the air cleaner if necessary.
13. Start the engine and leave it to work at single turns.

When performing any works in a motive compartment at the working engine be extremely careful. Besides high probability of receiving burns from the heated details of the engine or system of release, you risk to suffer a serious injury from the rotating details (for example, the fan of a radiator or a driving belt). Before work, first of all take measures and observe safety measures stated at the beginning of each Chapter. You watch the hands, do not allow hit of long hair or clothes in a motive compartment. You steer clear of system of release and other hot details.

14. Following from an air inlet to the air cleaner and further to a throttle, be convinced of lack of leaks from air supply hoses (including nearby vacuum hoses). They can be found on characteristic whistle. If whistle does not sound, apply a small amount of soap water on suspicious section of a hose. If the hose is damaged, kind of work of the engine will change, and on the processed surface of a hose there will be bubbles (or, depending on pressure in a hose, water can begin to be soaked up inside). At leak detection reliably tighten a collar or replace the damaged hose.
15. Similarly check all system of release (from a collector to back section). Be convinced of lack of leak of gases. For work simplification you can lift the car on the elevator, establish on a platform or over a hole. For conducting the simplest check stop up the outlet of system of release and listen to work of system. If you heard characteristic whistle, leak takes place. At detection of leak tighten the corresponding collar, bolts or nuts, replace laying or the burned-through section.
16. Further check consists in serial movement of each socket on the corresponding plug at the working engine. The unreliable contact will be determined by change of kind of work of the engine. Restore reliability of contact, having replaced or having cleared the corresponding socket. Keep in mind that in certain cases it is necessary to change the whole plaits.
17. If as a result of preliminary checks you did not find the reason of unstable operation of the engine, the car should be driven away on the station of service for performing more careful diagnostics with use of the special equipment.