5031279 JOHNSON CLIP

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A typical example of a C4.4 electronic control system (1) Fuel Pressure Sensor (2) Intake Manifold Air Temperature Sensor (3) Electronic Control Module (ECM) (4) Primary Speed/Timing Sensor (5) Oil Pressure Sensor (6) Oil Pressure Sensor (alternative location) (7) Secondary Speed/Timing Sensor (8) Solenoid for the Fuel Injection Pump (9) Intake Manifold Pressure Sensor (10) Intake Manifold Pressure Sensor (alternative location) (11) Coolant Temperature SensorNote: If equipped, the wastegate solenoid is installed on the right side of the engine.
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Table 1
Connector     Function    
P1     Machine Harness to ECM Connector (64 Pin Connector)    
P2     Engine Harness to ECM Connector (64 Pin Connector)    
P532     Fuel Pump Solenoid Connector (Two-Pin Connector)    
P402     Secondary Speed/Timing Sensor (Two-Pin Connector)    
P401     Primary Speed/Timing Sensor (Two-Pin Connector)    
P201     Engine Oil Pressure Sensor (Three-Pin Connector)    
P228     Fuel Pressure Sensor (Three-Pin Connector)    
P200     Intake Manifold Pressure Sensor (Three-Pin Connector)    
P103     Intake Manifold Temperature Sensor (Two-Pin Connector)    
P100     Coolant Temperature Sensor (Two-Pin Connector)    
J23     Diagnostic Connector (if equipped)    
P691/J691     Electronic Unit Injectors for No. 1 and No. 2 Cylinders (Four-Pin Connector)    
P692/J692     Electronic Unit Injectors for No. 3 and No. 4 Cylinders (Four-Pin Connector)    
P511     Wastegate Valve, if equipped (two-Pin Connector)    The C4.4 engine was designed for electronic control. The engine has an Electronic Control Module (ECM), a fuel injection pump and electronic unit injectors. All of these items are electronically controlled. There are also a number of engine sensors. Turbocharged engines can be equipped with an electronically controlled wastegate for the turbocharger. The ECM controls the engine operating parameters through the software within the ECM and the inputs from the various sensors. The software contains parameters that control the engine operation. The parameters include all of the operating maps and customer-selected parameters.
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The electronic control system has the following components:
ECM
Pressure Sensors
Temperature Sensors
Crankshaft Position Sensor
Secondary Position Sensor
Solenoid for the Fuel Injection Pump
Wastegate Solenoid
Electronic Unit InjectorsECM
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Typical exampleThe Electronic Control Module (ECM) (1) functions as a governor and a computer for the fuel system. The ECM receives signals from the sensors in order to control the timing and the engine speed.The electronic system consists of the ECM, the engine sensors, and inputs from the parent machine. The ECM is the computer. The personality module is the software for the computer. The personality module contains the operating maps. The operating maps define the following characteristics of the engine:
Engine power
Torque curves
Engine speed (rpm)
Engine Noise
Smoke and EmissionsThe factory passwords restrict changes to authorized personnel. Factory passwords are required to clear any event code. Refer to the following Troubleshooting, "Factory Passwords" For more information on the passwords.The ECM has an excellent record of reliability. Any problems in the system are most likely to be the connectors and the wiring harness. The ECM should be the last item in troubleshooting the engine.The personality module contains the software with all the fuel setting information. The information determines the engine performance.Flash programming is the method of programming or updating the personality module. Refer to the following Troubleshooting, RENR2417, "Flashing Programming " for the instructions on the flash programming of the personality module. The ECM is sealed and the ECM needs no routine adjustment or maintenance.Machine Security System (MSS) (if equipped)
The electronic control module will not allow the engine to start if the MSS is armed. If the MSS is armed, a lamp on the control panel will be illuminated. The status of the MSS can be viewed on the electronic service tool.Engine Speed Governor
The electronic controls determine the injection timing, the amount of fuel that is delivered to the cylinders. The electronic controls also determine the intake manifold pressure if an electronically controlled wastegate is installed on the turbocharger. These decisions are based on the actual conditions and the desired conditions at any given time.The governor has software that compares the desired engine speed to the actual engine speed. The actual engine speed is determined through the primary speed/timing sensor and the secondary speed/timing sensor. If the desired engine speed is greater than the actual engine speed, the governor injects more fuel in order to increase engine speed.Timing Considerations
Once the governor has determined the amount of fuel that is required, the software must determine the timing of the fuel injection. Fuel injection timing is determined by the ECM after considering input from the following components:
Engine coolant temperature sensor
The sensor for the intake manifold air temperature
The sensor for the intake manifold pressureAt start-up, the ECM determines the top center position of the number 1 cylinder from the secondary speed/timing sensor in the fuel injection pump. The ECM decides when fuel injection should occur relative to the top center position. The ECM optimizes engine performance by control of the electronic unit injectors so that the required amount of fuel is injected at the precise point of the engine cycle. The electronic unit injectors are supplied high-pressure fuel from the fuel injection pump. The ECM also provides the signal to the solenoid in the fuel injection pump. The solenoid in the fuel injection pump controls a valve in the fuel injection pump. This valve controls the pressure in the fuel injection pump. Fuel that is not required for the engine is diverted away from the fuel injection pump back to the fuel tank.The ECM adjusts injection timing and fuel pressure for the best engine performance, the best fuel economy, and the best control of exhaust emissions. The actual timing can be viewed with an electronic s