MODULE-POWER 4985438 - Caterpillar

Sensor Locations for the Clean Emissions Module
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Sensors and components on a typical Clean Emissions Module (CEM)
(1) DPF outlet pressure connection
(2) DPF intake pressure connection
(3) DOC intake temperature sensor
(4) DPF intake temperature sensor
(5) DPF outlet temperature sensor ECM
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Typical example
The Electronic Control Module (ECM) (1) functions as a computer for the fuel system.The electronic system consists of the ECM, the engine sensors, and inputs from the application. The ECM is the computer. The flash file is the software for the computer. The flash file contains the operating maps. The operating maps define the following characteristics of the engine:
Engine rating
Torque curves
High and low idle speed (rpm)
EmissionsThe 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 programmable software contains all the fuel setting information. The information determines the engine performance.Flash programming is the method of programming or updating the programmable software. Refer to Troubleshooting, "Flash Programming" for the instructions on the flash programming of the programmable software.The ECM is sealed and the ECM needs no routine adjustment or maintenance.Engine Speed
The ECM has software that compares the desired engine speed to the actual engine speed. The actual engine speed is determined through the crankshaft speed sensor. If the desired engine speed is greater than the actual engine speed, the ECM will instruct the fuel injection pump to supply more fuel to the fuel injectors in order to increase engine speed.Fuel Injection
The programmable software inside the ECM sets certain limits on the amount of fuel that can be provided to the fuel injectors.The ECM controls the following characteristics:
Operation of the NOx reduction system (if equipped)
RegenerationDiagnostic Codes
When the ECM detects an electronic system problem, the ECM generates a diagnostic code. Also, the ECM logs the diagnostic code in order to indicate the time of the problem's occurrence. The ECM also logs the number of occurrences of the problem. Diagnostic codes are provided in order to indicate that the ECM has detected an electrical problem or an electronic problem with the engine control system. In some cases, the engine performance can be affected when the condition that is causing the code exists.If the operator indicates that a performance problem occurs, the diagnostic code may indicate the cause of the problem. Use a laptop computer to access the diagnostic codes. The problem should then be corrected.Event Codes
Event Codes are used to indicate that the ECM has detected an abnormal engine operating condition. The ECM will log the occurrence of the event code. This does not indicate an electrical malfunction or an electronic malfunction. If the temperature of the coolant in the engine is higher than the permitted limit, then the ECM will detect the condition. The ECM will then log an event code for the condition.Speed Sensors
The engine has two speed sensors installed to measure crankshaft speed.
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Typical example
The primary speed sensor (1) is located on the left-hand side of