BOLT 0V0269 - Caterpillar

Illustration 1 g00527842
Electrical components of the PEEC III System (1) Timing solenoid (2) Rack solenoid (3) Electronic Control Module (ECM) (4) Coolant sensor (5) Transducer module (6) Ratings personality moduleThe Programmable Electronic Engine Control III System (PEEC III) is integrally designed into the engine fuel system to electronically control the fuel delivery and the injection timing.The following components are the major components of the PEEC III system:
Timing Solenoid (BTM) (1)
Rack Solenoid (BTM) (2)
Ratings Personality Module (6)
Transducer Module (5)
ECM (3)
Vehicle Speed Buffer
several sensorsThe PEEC III system uses three types of components:
input
control
outputAn input component is a component that sends an electrical signal to the electronic control module of the system. The signal varies in either voltage or in frequency in response to a change in some specific system of the vehicle. The electronic control module sees the input sensor signal as information about the following items:
the condition of the engine
the environment of the engine
the operation of the engineA control component receives the input signals. Electronic circuits that are inside the control evaluate the signals. The electronic circuits supply the electrical energy to the output components of the system. The supply of electrical energy is in response to the preset combinations of input signal values.An output component is a component that is operated by a control module. The output component receives electrical energy from the control group. The electrical energy is used to accomplish one of the following tasks:
The electrical energy can perform work so that the energy helps in regulating or in operating the vehicle.
The electrical energy can provide information or a warning to the operator of the vehicle or to another person.These components provide the ability to electronically control the engine operation in order to achieve the following tasks:
improved performance
improved fuel economy
improved driveability
reduced level of emissionsPEEC III System
The PEEC III 3406C Diesel Truck Engine is an electronically controlled 3406C. The PEEC III system controls the fuel rate and the timing electronically. The PEEC III system does not use flyweights and linkages. The electronics also replace the following components:
mechanical fuel air ratio control
torque control group
various adjustment screwsPEEC III uses several sensors as inputs to control two basic functions:
rack position
timing positionThe operation of each of these solenoids is similar. The PEEC III system calculates the correct position of the rack and the correct timing advance. The PEEC III system then varies the voltage to the solenoid (BTM) in order to move the rack or the timing advance to the desired position. Position sensors tell the PEEC III system when the rack or the timing is at the desired position.Electronic Controls
The electronic controller consists of two main components:
Electronic Control Module (ECM)
Personality ModuleThe ECM is the computer which controls the PEEC III engine. The personality module is the software which controls the computer's behavior. The two must be used together. Neither component can function alone.Rack Controls
The rack mechanism on a PEEC III engine is very similar to a mechanical 3406C engine. The fuel injection pump is nearly identical. The rack is moved by a