Jeep Grand Cherokee

1993-1999 of release

Repair and operation of the car



Jeep Grand Cherokee
+ Cars of the Jeep Grand Cherokee brand
+ Settings and routine maintenance
+ Line six-cylinder engine
+ V8 engine
+ Procedures of the general and capital repairs of the engine
+ Cooling systems, heating and air conditioning
+ A 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 multiposition injection of fuel (MPFI) and information sensors - the description
   Removal and installation of the electronic module of management (RSM)
   Description of the principle of action of system of self-diagnostics and procedure of reading of codes of malfunctions
   Information sensors
   System of the operated ventilation of a case (PCV)
   System of recirculation of the fulfilled gases (EGR)
   System of catching of vapors of fuel (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 methods of operation



Information sensors

Oxygen sensor

General description

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 determination of content of oxygen in the fulfilled gases. The oxygen which is contained in the fulfilled gases influences a sensitive element of the sensor, forcing the last to develop tension which level varies from 0,1 B (high content of oxygen, poor mix) to 0.9 B (low content of oxygen, rich mix). RSM continuously analyzes an output signal of the sensor, determining by it the content of air in gas mixture and correcting quality of mix by management of impulse width (time duration) of inclusion of injectors of fuel. The most optimum from the point of view of minimization of 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 composition of mix ideal conditions for effective operation of the catalytic converter are created. RSM and the oxygen sensor seek to support constantly such share ratio of mix (14.7 to 1).

The oxygen sensor begins to develop tension only on reaching the normal working temperature (about 320 °C). At the initial stage (before warming up of the sensor) after start of the RSM engine works in the mode of the opened contour.

If after an engine warming up up to the normal working temperature or work it within not less than two minutes the oxygen sensor begins to develop a steady signal amplitude below 0:45 In with a 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 contour of the RSM oxygen sensor will also establish a code 21.

At emergence of any failures of the O2 sensor or its contour of RSM automatically passes into the mode of an open contour that means support of supply of fuel in the programmed quantity without adjustment according to sensor signals.

Functioning of the oxygen sensor directly depends on four factors:

  • Electric - the Low voltage developed by the sensor depends on purity and quality of electric contacts which condition should be checked first of all at emergence of suspicions for refusal of functioning of the sensor.
  • Supply of external air - the Design of the sensor provides air circulation in it. Every time at removal of the sensor and its replacement before installation it is necessary to make sure of passability of air channels.
  • Adequacy of temperature of functioning - RSM will not react to sensor signals until temperature of the last on reaches working value about 320 °C. This factor surely has to be taken into account at 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. Fuel the car only unleaded.

In addition to need of performance of the listed above conditions during the work with the sensor it is necessary to observe special precautionary measures.

  • The oxygen sensor is equipped with the sockets which are constantly connected to it (electric and like "a piggy tail") which should not be disconnected from it. Damage or removal of any of them is fraught with adverse effects on functioning of the sensor.
  • It is necessary not to allow hits in the electric socket on the site of the valve of lubricant and other pollution equipped with blinds.
  • Do not apply any solvents to cleaning of the oxygen sensor.
  • Handle with the sensor with care - do not strike and do not stir up it.
  • The silicon protective cover has to be established correctly in order to avoid an oplavleniye and for the purpose of ensuring normal functioning of the sensor.

Check

 PERFORMANCE ORDER

  1. Find the electric socket of the oxygen sensor and insert the long probe into an opening of a black-orange wire (a wire of alarm tension).
  1. Insert the long probe into the electric socket of the oxygen sensor and test a black-orange wire of the socket for presence of tension of an output signal. Increase engine turns, trying to obtain increase in level of tension.
  1. Connect the positive probe of the voltmeter to the probe, ground the negative probe.

Additional information on coloring of wires of the oxygen sensor can be gathered from electric circuits at the end of the Head Sistem of onboard electric equipment.

  1. You watch instrument readings (adjusted on a millivoltny scale) in the course of an engine warming up (from a cold state).
  2. At first (at the cold engine) the oxygen sensor will develop a stable signal level near (0.1 - 0.2) In (the mode of the opened contour). About two minutes later the engine will reach the normal working temperature and the indication of the voltmeter (a sensor signal) have to begin to fluctuate within (0.1 - 0.9) In (the mode of the closed contour). If the sensor does not enter the mode of the closed contour, or on it leaves too long time, replace it.
  3. Also check functioning of the heater of the oxygen sensor. Disunite the electric socket of the sensor and connect an ohmmeter between two of its white wires. Resistance about 5 - 7 Ohms has to be registered.
  1. Measure resistance of the built-in heater of the oxygen sensor, having connected an ohmmeter between two white wires (the lower plugs of the socket). It has to make about 5 - 7 Ohms.
  1. Check giving of food to the 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 position of ON, the engine is not started) it has to equal to battery tension. If food is absent, check a contour between the main relay, RSM and the sensor.

It is important to remember that supply voltage moves only within two seconds as the system uses the relay for tension deviation (the air conditioner relay).

  1. If the oxygen sensor does not pass any of the listed checks, replace it.

Replacement

As the oxygen sensor is installed in a final collector or a reception pipe of system of production of the fulfilled gases which when cooling contract, to turn out it at the cold engine it can appear very difficult. In order to avoid risk of damage of the sensor at removal (if only you are not going to replace it anyway) previously start the engine for a couple of minutes. Be careful - do not burn in the course of implementation of the procedure about the warmed surfaces of components of system of production of the fulfilled gases.


 PERFORMANCE ORDER

  1. Disconnect a negative wire from the battery.
  2. The car also establish to Poddomkratta it on props.
  3. Carefully disunite the electric socket of the sensor.
  4. Accurately turn out the sensor from a final collector.
  5. For simplification of the subsequent removal of the sensor before installation grease its carving part with the anti-taking sealant. The carving of the new sensor is usually already greased with such sealant, however in case of installation to the place of the old sensor it is necessary to cover it anew.
  6. Install the sensor and strongly tighten it.
  7. Connect the electric socket (or a wire like "piggy tail") to the main plait of wires of the engine.
  8. Lower the car on the earth and make its trial runs and check of record of codes of diagnostics of malfunctions.

The sensor of absolute pressure in the pipeline (MAR)

General description

The MAR sensor monitors the changes of pressure in the inlet pipeline resulting from change of loads of the engine and the speed of the movement of the car and will transform the removed information to output 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 obtains information in the form of amplitude (on tension) a signal which level can change ranging from 1.0 to 1.5 B at the closed butterfly valve (deep depression) and from 4.0 to 4.5 In at opened (weak depression). The MAR sensor is located in the box-shaped casing fixed on a partition of a motive compartment.

The failure of the MAR sensor leads to record in memory of the module of management of a code of malfunction 13 or 14.

Check

 PERFORMANCE ORDER

  1. ON engines of 4.0 l check the vacuum hose going from the throttle case to the MAR sensor for existence of cracks and signs of aging of material. In case of need make replacement. The vacuum hose of the MAR sensor is connected to the inlet pipeline. The MAR sensor on the 5.2 l engines receives pipeline air from the union in a casing of the case of a throttle is connected to pipeline air via the union on the throttle case).
  2. Make sure of reliability of fastening of the electric socket of the sensor. Also check socket plugs for existence of traces of corrosion and reliability of fastening of wires to them. Examine conducting. In case of need make necessary repair.
  3. Disunite the electric socket of the MAR sensor, turn the ignition key in position of ON (the engine do not start) and check tension on a basic wire (between violet-white (+) and weight). It has to equal about 5 Century.
  1. By means of the voltmeter check basic tension on a violet-white wire (+) - it has to equal about 5 Century.
  1. Connect the socket to the sensor and measure tension on an alarm wire (red-white) at the included ignition (a key in position of ON, the engine is not started). It has to lie in limits between 4.0 and 5.0 V. Eto verification of the signal transmitted by the sensor to RSM.
  1. Without depression (the engine is switched off) check tension on a red-white wire of the MAR sensor. It has to equal approximately (4.0 - 5.0) Century.
  1. On models of 5.2 l start the engine and, having left it working at single turns, test a red-white alarm wire of the sensor the positive probe of the voltmeter. Tension has to fall approximately to value in (1.5 - 2.5) In in process of discharge deepening. If instrument readings do not correspond to this value, replace the MAR sensor.

On engines of 4.0 l for creation of depression on the MAR sensor use the manual vacuum pump.


  1. Then start the engine and, having left it working at single turns, measure MAR sensor tension - it has to lie within 1.5 - 2.5 In (with increase in depth of depression tension has to fall).

Replacement

 PERFORMANCE ORDER

  1. On engines of 4.0 l disunite the electric socket and disconnect a vacuum hose from the sensor.
  2. Give fixing bolts and remove the MAR sensor from the throttle case (engines of 5.2 l) or a partition of a motive compartment (4.0 l).
  1. Give bolts (shooters) of fastening of the MAR sensor to the throttle case (the engine of 5.2 l).
  1. You make installation upside-down.

Sensor of provision of a bent shaft

General description

On cars of these models the sensor of provision of a bent shaft serves for definition of distribution of injection of fuel in cylinders and its ignition in combustion chambers. This work is also performed by RSM. The sensor represents the device working at Hall's effect, installed on a dome of transmission and which is carrying out calculation рисок on a flywheel (RKPP) or a flexible disk (AT). If RSM ceases to obtain information from the sensor of provision of a bent shaft, the engine will stop functioning.

Components of the sensor of provision of a bent shaft - the engine of 4.0 l.

Components of the sensor of provision of a bent shaft - the engine of 5.2 l.

Check

 PERFORMANCE ORDER

  1. Connect an ohmmeter between plugs B and C of the electric socket of the sensor of provision of a bent shaft. Infinite resistance has to be fixed.
  1. The ohmmeter connected between plugs B and C of the socket of the sensor of provision of a bent shaft has to show infinity.
  1. If the ohmmeter shows low resistance, replace the sensor.

Replacement

Line six-cylinder engine

 PERFORMANCE ORDER

  1. Disunite the electric socket of a plait of wires of the sensor of provision of a bent shaft.
  2. On models of 1994 of the issue equipped with AT the sensor it is fixed by means of the only bolt And the bolted opening of the sensor has a cut. If you plan to use further the old sensor, mark the exact provision of a bolt in relation to the sensor for a guarantee of installation them at assembly absolutely similarly. For Installation of the new sensor on the required depth use the remote washer (attached in a set to the new sensor). If the gap between the sensor and a flywheel is exposed incorrectly, at start of the engine there will be a damage of the sensor. On all models use for fastening of the sensor only the bolts attached to them as they are processed so that to provide the required gap between the sensor and a flywheel.
  3. Give a fixing bolt(s) and remove the sensor.
  4. You make installation upside-down. Tighten fixture with the required effort.

V8 engines

 PERFORMANCE ORDER

  1. Remove wires from spark plugs of the right number of cylinders. Before removal take care of accurate marking of each wire. Disconnect wires from a fixing hairpin in a back part of a cover of a head of cylinders and put them aside.
  2. Remove the thermofilter of the right final collector (the Head the V8 Engine).
  3. Pick up the valve and the phone of EGR (see an illustration). For ensuring access to a tube nut in case of need remove the oil pressure sensor block.
  4. Disunite the electric socket of a plait of wires of the sensor of provision of a bent shaft, give fixing bolts and remove the sensor.
  5. You make installation upside-down. Tighten fixture with the required effort.

Sensor of temperature of a cooler (CTS)

General description

The sensor of temperature of a cooler represents a thermistor (the resistor which resistance changes depending on temperature). Change of resistance of the sensor directly influences the level of tension of its output signal. With REDUCTION of temperature of the sensor its resistance INCREASES and vice versa. The refusal in a contour of CTS leads to record in memory of the module of a code of malfunction 22. In case of highlighting of such code during diagnostics of malfunctions of system in most cases the correct decision is replacement of the sensor or an electrical wiring of its contour.

Check

 PERFORMANCE ORDER

  1. For check of the sensor perform measurement of its resistance at first in a cold state (at a temperature of 10 - 27 °C resistance of the sensor has to make 17.900 - 10.800 Ohms). Then start the engine and warm up it up to the normal working temperature. Resistance of CTS has to fall (at a temperature of 83 - 94 °C = 1.170 - 820 Ohms).

Measurement of resistance of CTS on model of 4.0 l.

  1. Access to CTS on engines of 5.2 l is extremely complicated. For check of resistance of the sensor at first remove the generator, then the air conditioner compressor.
  1. Check basic tension at the included ignition (without starting the engine). It has to make about 5.0 Century.
  1. By means of the voltmeter check the basic tension of CTS. It has to make about 5.0 Century.

Replacement

Before starting performance prots2edury wait for full cooling of the engine.


 PERFORMANCE ORDER

  1. Before installation of the new sensor wrap up its carving part a teflon sealing tape (or the film FUM) which is designed to prevent development of corrosion and leaks in a sensor carving further.
  2. For removal of the sensor press a lock uvula and disunite the electric socket, then carefully unscrew the sensor. In order to avoid noticeable losses of a cooler as soon as possible screw the new sensor.

Handle CTS with care. Damage of the sensor is capable to affect functioning of all system of injection of fuel.


Location of CTS on engines of 4.0 l.


  1. On models of 5.2 l at first, for ensuring access to CTS, remove the generator and the compressor of the air conditioning system.
  1. You make installation upside-down.

Sensor of provision of a butterfly valve (TPS)

General description

The sensor of provision of a butterfly valve (TPS) is located at an end face of an axis of a butterfly valve on the throttle case. By tracking of an output signal of the RSM sensor determines supply of fuel by a corner of position of the gate (is operated by the driver). An exit of TPS is out of operation fraught with violation of stability of injection of fuel injectors and idling turns as RSM will believe that the gate moves.

Check

 PERFORMANCE ORDER

  1. Find TPS on the throttle case.
  2. By means of the voltmeter check basic tension from RSM. Connect the positive probe of the fan to violet white wire, and negative - to black blue. Instrument readings have to equal about 5.0 Century.
  1. Measure basic tension between violet-black (basic) and black-blue (weight) TPS wires. It has to equal about 5.0 Century.
  1. Further connect the electric socket to the sensor and measure its alarm tension. At completely closed butterfly valve connect the voltmeter between an orange-blue wire of the sensor and weight. Watching instrument readings, slowly open the gate. At completely closed gate tension of the sensor has to make about 0.5 Century. On full gas tension has to increase up to value about 4.5 - 5.0 Century. In case of obtaining the wrong indications replace the sensor.
  1. Measure the alarm tension of TPS between orange-blue (alarm) and black-blue (weight) sensor wires. At first measure tension at completely closed butterfly valve - it has to equal about 5.0 Century.

  1. Then manually open the gate against the stop and consider the indication of the voltmeter - now it has to make about 3.5 - 5.0 Century.
  1. Emergence of any sort of problems in a contour of TPS leads to record in memory of the module of management of a code of malfunction 24. Immediately after input of the RSM code begins to use an artificial signal of provision of a butterfly valve that allows to restore partly operational parameters of the engine, again having increased overall performance of the last.

Replacement

 PERFORMANCE ORDER

  1. Disconnect a negative wire from the battery.
  2. Give on TPS bolts with heads like TORX and remove the sensor from the throttle case.
  1. Give bolts with heads like TORX (arrow) of fastening of TPS.
  1. At installation of the sensor track correctness of combination of the directing nest uvulas on TPS with a gate axis in the throttle case.
  1. Before the TPS installation take care of the correct combination of the directing uvulas in it with a gate axis end face in the throttle case (the engine of 4.0 l is shown).
TPS installation details on engines of 5.2 l.
  1. You make installation upside-down.

Air temperature sensor

General information

The sensor of air temperature is located in the inlet pipeline. Sometimes this sensor is called also "the sensor of change of air temperature" or "the sensor of air temperature of the pipeline (IAT)". The sensor functions as the device with negative temperature coefficient (NTC) that means that at REDUCTION of temperature of the sensor its resistance INCREASES and vice versa. Most often in case of problems in this contour their elimination requires repair or replacement of the sensor.

Check

 PERFORMANCE ORDER

  1. For check of the sensor at first measure its resistance in a cold state (at a temperature of 10 - 27 °C resistance of the sensor has to make 17.900 - 10.800 Ohms). Then start the engine and warm up it up to the normal working temperature. Resistance of CTS has to fall (at a temperature of 83 - 94 °C = 1.170 - 820 Ohms). At the switched-off ignition (a key in position of OFF) disunite the electric socket of the sensor of air temperature which is located on the inlet pipeline. Then by means of an ohmmeter measure resistance between two plugs of the sensor.

Check of resistance of the sensor of air temperature on the engine of 4.0 l.

Check of resistance of the sensor of air temperature on the engine of 5.2 l.
  1. Having included ignitions (but without starting the engine) measure the basic tension of the sensor - it has to make about 5.0 Century.

Check of basic tension of the sensor of air temperature on the engine of 5.2 l.

  1. If results of check are negative, replace the sensor.
  2. If check did not reveal malfunctions of the sensor, and the problem still takes place, drive away the car in dealer office or a workshop of car service for carrying out failure diagnostics of RSM.

Replacement

 PERFORMANCE ORDER

  1. Disunite the electric socket of the sensor of air temperature.
  2. Give fixing screws and remove the sensor from the inlet pipeline.
  3. You make installation upside-down.

Sensor of speed of the car (VSS)

General description

VSS is located or on the transfer case, or on transmission, depending on model of the car and its equipment. It represents the sensor with the rotating permanent magnet which begins to develop pulse tension when speeding the movement of the car of value in 5 km/h (3 miles/hour). Impulses are broadcast to RSM and used for management of functioning of other systems (food and gear shifting).

Check

 PERFORMANCE ORDER

  1. For check of VSS disunite the electric socket of a plait of wires in the neighbourhood with the sensor. By means of the voltmeter measure the basic tension of the sensor - it has to equal about 5.0 In (or a little more). If tension is absent, drive away the car in a workshop of dealer office for diagnostics of malfunctions of RSM.
  1. Connect the positive probe of the voltmeter to basic (white-black) to a sensor wire, the negative probe - to a wire of grounding (black-blue).

Replacement

 PERFORMANCE ORDER

  1. For replacement of VSS disunite its electric socket.
  2. Give a fixing bolt and remove the sensor from transmission.

Otdavaniye of VSS fastening bolt.

  1. You make installation upside-down.

Electromagnet of management of blocking

General description

The electromagnet of management of blocking represents the actuation mechanism operated by the processor which is used to turning on of the mechanism of blocking of the converter of rotation on the cars equipped with AT. In more detail about procedures of check and replacement see in the Head Automatic transmission.

Sensor of position of the camshaft

The description of procedures of check and replacement of the sensor see in the Head Sistema of electric equipment of the engine.

Sensor switch of permission of start

The description of procedures of check and replacement of the sensor switch see in the Head the Manual box of gear shifting.