Jeep Grandee Cheroki
+ Jeep Grand Cherokee brand Cars
+ Settings and routine maintenance
+ Ryadny six-cylinder engine
+ V8 Engine
+ Procedures of the general and major maintenance of the engine
+ Systems of cooling, heating and air conditioning
+ the Power supply system and production of the fulfilled gases
+ System of electric equipment of the engine
- Systems of decrease in toxicity of the fulfilled gases and engine management
General information
System of multiitem injection of fuel (MPFI) and information sensors - the description
Removal and installation of the electronic module of management (RSM)
Description of a principle of action of system of self-diagnostics and procedure of reading of codes of malfunctions
Information sensors
System of operated ventilation of a case (PCV)
System of a retsirkulyatsiya of the fulfilled gases (EGR)
Catching system паров fuels (EVAP)
Catalytic converter
+ Manual box of gear shifting
+ Automatic transmission
+ Transfer case
+ Coupling and transmission line
+ Brake system
+ Suspension bracket and steering
+ Body
+ System of onboard electric equipment
+ Governing bodies and operation receptions
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Information sensors
Oxygen sensor
General description
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Access to the oxygen sensor on engines of 5.2 l is very complicated. Space between the electric socket of the sensor and a final collector too for a prosovyvaniye of hands in it. Thus diagnostic check is possible only in the conditions of a workshop of dealer office or by means of the scanner. |
The oxygen sensor is located in a final collector and serves for definition of the content of oxygen in the fulfilled gases. Oxygen containing in fulfilled gases influences a sensitive element of the sensor, forcing the last to develop the tension which level varies from 0,1 In (the high content of oxygen, a poor mix) to 0.9 In (the low content of the oxygen, a rich mix). RSM continuously analyzes a target signal of the sensor, determining by it the content of air in gas mixture and correcting quality of a mix by impulse management in width (duration of time) inclusions of injectors of fuel. The most optimum from the point of view of minimization of the content in the fulfilled gases of toxic components is the mix, consisting their 14.7 parts of air on 1 part of fuel. At such structure of a mix ideal conditions for effective operation of the catalytic converter are created. RSM and the oxygen sensor aspire to support constantly such share ratio of a mix (14.7 to 1).
The oxygen sensor starts to develop tension only on reaching the normal working temperature (about 320 ° C). At the initial stage (before sensor warming up) after start of the RSM engine works in a mode of the opened contour.
If after an engine warming up to normal working temperature or work it within not less than two minutes the oxygen sensor starts to develop a steady signal amplitude below 0.45 In at frequency of rotation of the engine of 1500 rpm or above, the RSM Module fixes a code 51 or 52. In case of identification of any problems in a RSM oxygen sensor contour also will establish a code 21.
At emergence of any failures of the O2 sensor or its contour of RSM automatically passes to a mode of an open contour that means podderzhivany supply of fuel in the programmed quantity without adjustment according to sensor signals.
Functioning of the oxygen sensor directly depends on four factors:
- The electric - the Low voltage developed by the sensor, depends on purity and quality of the electric contacts which condition should be checked first of all at emergence of suspicions on refusal of functioning of the sensor.
- Supply of external air - the Design of the sensor provides air circulation in it. Each time at removal of the sensor and its replacement before installation it is necessary to make sure of passableness of air channels.
- Adequacy of temperature of functioning - RSM will not react to sensor signals until the temperature of the last on will reach working value about 320 ° Page. This factor surely should be taken into consideration at an assessment of efficiency of functioning of the sensor.
- Unleaded fuel - This condition is extremely important from the point of view of serviceability of functioning of the sensor. Fill the car with only unleaded fuel.
In addition to need of performance listed above conditions at work with the sensor it is necessary to observe special precautionary measures.
- The oxygen sensor is equipped with sockets constantly connected to it (electric and such as «a piggy tail») which should not be disconnected from it. Damage or removal of any of them is fraught with adverse effects on sensor functioning.
- It is necessary not to allow hits in the electric socket on the site of the valve of greasing equipped with a jalousie and other pollution.
- Do not apply to cleaning of the oxygen sensor some any solvents.
- Address with the sensor carefully - do not strike and do not stir up it.
- The silicon protective cover should be established correctly in order to avoid an oplavleniye and for the purpose of ensuring normal functioning of the sensor.
Check
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- Find the electric socket of the oxygen sensor and insert into an opening of a black-orange wire (a wire of alarm tension) the long probe.
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- Insert into the electric socket of the oxygen sensor the long probe and test a black-orange wire of the socket for existence of tension of a target signal. Increase engine turns, achieving increase of level of tension.
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- Connect positive щуп the voltmeter to the probe, negative щуп earth.
- Watch instrument readings (adjusted on a millivoltny scale) in the course of an engine warming up (from a cold condition).
- At first (at the cold engine) the oxygen sensor will develop a stable signal level near (0.1 - 0.2) In (a mode of the opened contour). About two minutes later the engine will reach normal working temperature and the voltmeter indication (a sensor signal) should start to fluctuate in limits (0.1 - 0.9) In (a mode of the closed contour). If the sensor does not enter into a mode of the closed contour, or on it leaves too long time, replace it.
- Also check functioning of a heater of the oxygen sensor. Disunite the electric socket of the sensor and connect between its two white wires an ohmmeter. Resistance about 5-7 Ohm should be registered.
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- Measure resistance of the built-in heater of the oxygen sensor, having connected an ohmmeter between two white wires (the bottom plugs of the socket). It should make about 5-7 Ohm.
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- Check food giving to a heater. Measure for this purpose tension between orange-black (+) and black-blue (-) wires of the electric socket of the oxygen sensor. At the included ignition (a key in the situation ON, the engine is not started) it should equal to tension of the battery. If a food is absent, check a contour between the main relay, RSM and the sensor.
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It is important to remember that the supply voltage moves only within two seconds as the system uses the relay for a tension deviation (the relay of the conditioner of air). |
- If the oxygen sensor does not pass any of the listed checks, replace it.
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Replacement
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As the oxygen sensor is established in a final collector or a reception pipe of system of production of the fulfilled gases, which when cooling are compressed, turn out it at the cold engine it can to appear very difficult. In order to avoid risk of damage of the sensor at removal (if only are not going to replace it in any case) previously start the engine for few minutes. Be careful - do not burn in the course of procedure performance about the warmed-up surfaces of components of system of production of the fulfilled gases. |
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- Disconnect a negative wire from the battery.
- To Poddomkratta the car also establish it on props.
- Carefully disunite the electric socket of the sensor.
- Accurately turn out the sensor from a final collector.
- For simplification of the subsequent removal of the sensor before installation grease its carving part with anti-taking hermetic. The carving of the new sensor is usually already greased with such hermetic, however in case of installation to the place of the old sensor it is necessary to cover it anew.
- Establish the sensor and strongly tighten it.
- Connect the electric socket (or a type wire «a piggy tail») to the main plait of wires of the engine.
- Lower the car on the earth and make its trial runs and check of record of codes of diagnostics of malfunctions.
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The sensor of absolute pressure in the pipeline (MAR)
General description
The MAR sensor traces changes of pressure in the inlet pipeline, resulting changes of loads of the engine and speeds of movement of the car and will transform removed information to target tension. RSM uses the signals received from the MAR sensor for management of supply of fuel and correction of a corner of an advancing of ignition. RSM receives information in the form of peak (on tension) a signal which |