CLAMP AS 3284367 - Caterpillar

Electronic Control Module (ECM)
The Engine ECM bases decisions on input information and memory information. After the Engine receives the input information, the ECM sends a corresponding response to the outputs. The inputs and outputs of the ECM are connected to the machine harness by two 64 contact connectors (J1 and J2). The inputs and outputs to the ECM can be viewed through the Caterpillar Electronic Technician (Cat ET).In most instances when a diagnostic code or an event code is activated, the ECM is the least likely cause of the problem. When an ECM is suspected of failure, always ensure that the latest software is flashed on the ECM. Verify that the ECM connections are secure. Then, verify that the problem is still active before replacing an ECMNote: Only the complete ECM is serviced (no lower levels components). The ECM must be replaced if the ECM is damaged. Replace the ECM if a failure is diagnosed.Inputs
The machine has several different types of input devices. The ECM receives machine status information from the inputs devices and determines the correct output action that is needed in order to control machine operations based on memory and software parameters. the machine utilizes the following types of inputs: switch type and sensor type.Switches provide signals to the switch inputs of the ECM. The possible outputs of a switch are listed: an open signal, a ground signal and + battery signal.Sensors provide an electrical signal to the ECM that constantly changes. The sensor input to the ECM can be one of several different types of electrical signals such as: pulse width modulated (PWM) signals, voltage signals, and frequency input signals. Each possible input to the ECM is listed in the tablesSwitches
Reversible Fan Switch
Illustration 5 g03832074The reversing fan can be enabled or disabled using Cat ET. By default the reversing fan is enabled. If the reversible fan switch is pressed, the light will blink and the engine ECM will engage the reverse mode for the fan. If the light is solid, the fan is in "Auto" mode and the fan will reverse for a predetermined time on a set interval. The reversing fan purge duration and intervals are adjustable using Cat ET or though the display of the machine, in the machine settings menu.Sensors
Hydraulic Oil Temperature
Illustration 6 g01113896The temperature sensor is a passive analog sensor. The signal voltage of the sensor corresponds to the temperature of the hydraulic oil. The voltage signal is an input to the Machine ECM. This voltage signal will vary representing changes in the hydraulic oil temperatures. The temperature of the sensor is displayed on the instrument cluster. The temperature is represented in either Metric units or English units. The temperature is accessible by scrolling through the display.Outputs
The ECMs respond to decisions by sending electrical signals to the outputs. The outputs can create an action or the outputs can provide information to the operator or the service technician.Solenoids
Illustration 7 g02747758
Typical example of a solenoid valve
(1) Pin 1
(2) Pin 2Demand Fan Proportional Solenoid Valve
The demand fan