Jeep Grand Cherokee

1993-1999 of release

Repair and car operation



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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System of multiitem injection of fuel (MPFI) and information sensors - the description

The system of multiitem injection of fuel (MPFI) provides giving in the engine of demanded quality of a mix under any service conditions of the car. Injectors of system provide fuel injection in each of inlet ports.

Brain of system of injection is the module of management of RSM. RSM is located in a forward corner of an impellent compartment.

RSM receives and processes peak (on tension) signals from a set of various sensors, switches and the relay. All entering signals will be transformed to the figures which are read out by the module of management, carrying out on the basis of their analysis continuous thin fine tuning of such major parameters of the engine, as a corner of an advancing of ignition, duration of inclusion of a current of the coil of ignition, duration of an impulse of inclusion of an injector and turns of idling of the engine for the purpose of minimization of pollution of the atmosphere by products of combustion and receiving the maximum return from the engine. Besides, RSM supervises operation of the fan of system of cooling, a charging current of the generator and such components of system of decrease in toxicity of the fulfilled gases, as electromagnets of EGR and a purge of a coal adsorber of EVAP system. RSM is capable to change also the program according to working conditions.

Components of systems of decrease in toxicity of the fulfilled gases and engine management of models of 4.0 l (for models of 5.2 l the scheme is similar)

1 — Д/В - the Sensor switch
2 — VSS - the Sensor of speed of the car
3 — Ø/m - the Electromagnet

4 — ASD Automatic shutdown of supply of fuel
5 — About/D - Raising transfer

RSM carries out continuous control of a set of own entrance and target contours. In case of malfunction emergence in MPFI system information on it is fixed in memory of the module. To make diagnostics of malfunctions of components of MPFI system without existence of special expensive factory manufacturing of the tool and the input reader of codes of malfunctions of DRB II (No. S-4805) or its equivalent it is not obviously possible, however in many cases it is possible to try to localize a source of suspected refusal, having limited a search circle at least to a concrete contour. This work always begins with reading of codes of malfunctions, then visual survey of components of system for the purpose of check of a condition and reliability of fastening of conducting and electric sockets is made. More often weakening of fastening or a detachment of terminal connections of electroconducting or vacuum lines appears a cause of failure. Instructions on a conclusion of diagnostic information from memory of RSM on a control lamp «Check the engine» the Description of a principle of action of system of self-diagnostics and procedure of reading of codes of malfunctions are provided in the Section.

Information sensors

Into number of a set of the sources which are handing over information on RSM enter:

  • Relay of the coupling of coupling of the conditioner of air
  • Relay of automatic shutdown of supply of fuel (ASD)
  • Sensor switch of stoplights
  • Sensor of provision of a camshaft
  • Air temperature sensor
  • Sensor of temperature of a cooler
  • Sensor of provision of a cranked shaft
  • The sensor of absolute pressure in the pipeline (MAR)
  • Oxygen sensor
  • Sensor of provision of a butterfly valve (TPS)
  • Sensor switch of permission of start (provision of transmission)
  • Sensor of speed of the car (VSS)

The relay of the coupling of coupling of the conditioner of air (To/in)

Operation of the relay of the coupling of coupling To/in RSM operates. Management is carried out at the expense of inclusion switching off of a contour of grounding of the relay. When RSM receives inquiry from the To/in control panel (a control system of climate), it gives command for turning on of the motor of system of stabilization of turns of idling (IAC) for the purpose of the corresponding correction of turns. The relay of management To/in is located coupling in power supply distribution center near the battery.

Location of distribution center of power supply.

Relay of automatic shutdown of supply of fuel (ASD)

If lack of a signal of ignition (distributor) or from sensors of provision of a distributive or cranked shaft takes place at ignition key turn in the situation RUN (Movement), the ASD relay disconnects a food of the electric fuel pump, injectors of fuel, the coil of ignition and the warmed-up oxygen sensor. The disconnecting relay is located in power supply distribution center near the battery.

Sensor of provision of a camshaft

The sensor of provision of a camshaft includes the semiconductor working at effect of the Hall, and gives out a signal used for synchronization of work of power supply systems and ignition. The synchronizing signal is developed by the semiconductor at rotation of a ring of the sensor with the screen, located in the distributor.

Sensor of provision of a camshaft of the engine of 4.0 l.

Air temperature sensor

The sensor of air temperature established in the inlet pipeline defines temperature of entering air and hands over the relevant information on RSM. Information is used by the module at correction of an air and fuel mix.

Location of the sensor of air temperature on the engine of 4.0 l.

Location of the sensor of air temperature on the engine of 5.2 l.

Sensor of temperature of a cooler

The sensor of temperature of the cooler, screwed in in the thermostat case, traces cooler temperature, sending the corresponding signals on RSM. These data together with information received from the sensor of air temperature are used by the module at correction of quality of gas mixture and idling turns in the course of an engine warming up. The sensor also serves for turning on of the fan обдува a radiator.

Location of the sensor of temperature of a cooler of the engine of 4.0 l.

Location of the sensor of temperature of a cooler of the engine of 5.2 l.

Sensor of provision of a cranked shaft

The sensor of provision of a cranked shaft fastens on a transmission dome. The sensor hands over information on the current provision of a cranked shaft on RSM. As basic data the sensor uses cuts on a driving disk of the converter of rotation or a flywheel.

Location of the sensor of provision of a cranked shaft of engines of 4.0 l equipped with AT.

Location of the sensor of provision of a cranked shaft of engines of 4.0 l equipped with RKPP.

The sensor of absolute pressure in the pipeline (MAR)

The MAR sensor is located on a partition or a wall of an impellent compartment. The sensor defines depth of depression in the inlet pipeline through the vacuum line connected to the case of a throttle. Taken readings the sensor transfers to RSM together with data on barometric pressure in the form of tension changing on amplitude. In a compartment with information obtained from other sensors these data allow the module of management to define demanded composition of gas mixture.

Location of the MAR sensor on the engine of 4.0 l.

Location of the MAR sensor on the engine of 5.2 l.

Various sensors switches

Sensors switches (such as the switch of permission of start, the conditioner of air, control of speed and stoplights) supply RSM with information allowing it to make adjustments of functioning of the engine depending on a condition of the various equipment (incl. / off). It is difficult to define indications of these sensors switches (high/low level of a signal) without a diagnostic measuring instrument of DRB II.

Oxygen sensor

The oxygen sensor located in a reception pipe of system of production of fulfilled gases (right on V8) engines, gives out peak (on tension) a signal depending on presence at system of production of the fulfilled gases of oxygen. For acceleration of an exit of the sensor in an operating mode at engine warming up the sensor is equipped with the built-in electric heater. If the fulfilled gases contain considerable percent of oxygen (a poor mix), the signal of the sensor has smaller amplitude; at the small content of oxygen (a rich mix) the amplitude of tension given out by the sensor raises. Tracing percent of the content in the fulfilled gases of oxygen and transferring it to an electric signal, the sensor works as the sensor switch of pauperization enrichment of gas mixture. The signal from the sensor arrives on RSM which on the basis of its analysis increases or reduces width of an impulse (duration) of inclusion of injectors of fuel.

Location of the oxygen sensor.

Sensor of provision of a butterfly valve (TPS)

Located in the case of a throttle of TPS defines a corner of a deviation of a butterfly valve. Tension developed by the sensor increases or decreases depending on width of opening of a zaslonka. Arriving on RSM this signal in a compartment with the data received from other sensors, allows the processor of the module to carry out correction of quality of a mix depending on operating conditions of the engine, such as acceleration / деселерация, work on single turns or at completely open butterfly valve.

Location of TPS (engine of 5.2 l).

Sensor of distance (speed) of the car (VSS)

VSS located on lengthening of a case of transmission or a transfer case (depending on car equipment), serves for determination of speed of movement of the car. The sensor develops eight impulses for each turn of a power shaft and transfers them to RSM. These signals are compared by the module to a signal of a closed position of a butterfly valve from TPS allow to distinguish conditions of closing of a zaslonka when dumping turns of the engine and at work of the last on single turns (on at the stop car) At a sbrasyvaniye of turns of the RSM engine carries out control of IAC motor functioning, achieving a demanded signal from MAR; at operation of the engine on single turns of RSM operates the IAC motor, supporting desirable frequency of rotation of the engine.

Location of VSS.