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| Illustration 1 | g00785019 |
Electronic Control Module (ECM) | |
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| Illustration 2 | g00987330 |
Location of Electronic Control Module (ECM) | |
The electronic control module is located on the inside of the engine enclosure.
The electronic control module (ECM) makes decisions that are based on input information and memory information. After the ECM 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 70 contact connectors (J1 and J2). The ECM sends the information to the Caterpillar Electronic Technician on the CAT data link.
Note: The ECM is not serviceable. The ECM must be replaced if the ECM is damaged. Replace the ECM if a failure of the ECM is diagnosed.
Inputs
The inputs describe the status of the machine systems. Two types of inputs exist. The inputs can be either a switch type or a sensor type. Switches provide an open, a ground, or a + battery signal to the inputs of the controller. Sensors (frequency, pulse width modulation or voltage) provide a changing signal to the sensor inputs of the controller. The inputs to the ECM are listed in table 1 and table 2.
Outputs
The ECM responds 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. The outputs of the machine ECM are listed in table 1 and table 2.
Data Links
The machine ECM supports three data links.
- Cat Data Link
- J1939 CAN Data Link
- PHS CAN Data Link
The three data links are the main structure for the communications between the machine ECM and any other ECM on the machine.
Input/Output
The CAT Electronic Technician (ET) is used in order to provide a connection for the service tool for troubleshooting, testing, and calibrations. The data link is bidirectional. The data link allows the ECM to receive information. The data link allows the ECM to send information.
| Contact Description J1 (1) | ||
|---|---|---|
| No. (2) | Function | Type |
| 10 | Cat Data Link + | CDL + |
| 13 | Machine Ground | Battery - |
| 20 | Cat Data Link - | CDL - |
| 34 | Boom Retracted Switch Parity | Switch To Ground |
| 40 | Left Stabilizer Raise | Switch To Ground |
| 41 | Left Stabilizer Hold | Switch To Ground |
| 42 | Left Stabilizer Lower | Switch To Ground |
| 43 | Boom Retracted Switch | Switch To Ground |
| 45 | Switch To Ground Return | 8V Sensor Return |
| 55 | Rear Axle Lock & Auxiliary Diverter Valve Return | Pulse Width Modulation |
| 57 | Machine Ground - | Battery - |
| 63 | Implement Disable Switch - Enable | Switch To Ground |
| 64 | Implement Disable Switch - Disable | Switch To Ground |
| 65 | Rear Axle Lock Solenoid | Pulse Width Modulation |
| 66 | Auxiliary Diverter Valve | Pulse Width Modulation |
| 69 | 10 Volt PHS Valve Power | 10 Volt Power Supply |
| 70 | Machine Ground (-) | Battery - |
| ( 1 ) | The ECM responds to an active input only when all the necessary conditions are satisfied. |
| ( 2 ) | The connector contacts that are not listed are not used. |
| Contact Description J2 (1) | ||
|---|---|---|
| No. (2) | Function | Type |
| 3 | Quick Coupler Relay | 2A On/Off Std -2 |
| 9 | Continuous Flow LED | 300mA Sink 1 |
| 10 | Frame Level Interlock Relay | 300mA Sink 2 |
| 11 | Rear Axle Lock Return Side Relay | 300mA Sink 3 |
| 12 | Engine Run Relay | 300mA Sink 4 |
| 13 | PHS Address Out | 300mA Sink 5 |
| 15 | Continuous Flow Switch | Switch To Ground |
| 23 | Auxillary 2 Select Switch | Switch To Ground |
| 29 | Right Stabilizer Raise | Switch To Ground |
| 30 | Right Stabilizer Hold | Switch To Ground |
| 31 | Right Stabilizer Lower | Switch To Ground |
| 32 | Joystick Longitudinal Command | Pulse Width Modulation |
| 33 | Joystick Thumb Slider Command | Pulse Width Modulation |
| 36 | Quick Coupler Switch - Engage | Switch To Ground |
| 37 | Quick Coupler Switch - Disengage | Switch To Ground |
| 38 | Quick Coupler Switch - Parity | Switch To Ground |
| 40 | Joystick Lateral Command | Pulse Width Modulation |
| 41 | Auxillary (+) | Switch To Ground |
| 44 | Right Stabilizer Pressure Switch | Switch To Ground |
| 45 | Left Stabilizer Pressure Switch | Switch To Ground |
| 47 | Boom Criticle Angle Switch | Switch To Ground |
| 55 | PHS Address (IN) | Switch To Ground |
| 61 | Boom Criticle Angle Switch Parity | Switch To Ground |
| 62 | Ausiliary - | Switch to ground |
| 64 | CAN B+ (Instr) J1939 | CAN B + |
| 65 | CAN B- (Instr) J1939 | CAN B - |
| 67 | CAN A+ (PHS Valve Stack) | CAN A + |
| 68 | CAN A- (PHS Valve Stack) | CAN A - |
| ( 1 ) | The ECM responds to an active input only when all the necessary conditions are satisfied. |
| ( 2 ) | The connector contacts that are not listed are not used. |