CB54, CB54 XW and CB64 Vibratory Compactors Propel System Caterpillar

Illustration 1	g01822273
Left Side of Machine (1) Machine ECM (2) Connector "J2" (3) Connector "J1"

Machine ECM (1) is located under the operator platform on the left side of the machine. The articulation area provides access to this component. The machine ECM has two 70-pin connectors. Connector "J1" (3) and connector "J2" (2) .

Machine ECM (1) controls the propel system. The ECM receives input signals from components around the machine which monitor current machine operating conditions. System software compares the gathered input to information which is stored in the ECM's memory. The software evaluates the current conditions and generates output signals in order to control the propel system within set parameters. The machine ECM communicates with the propel lever microprocessor through the CAN lines. The machine ECM communicates with the engine ECM through the CAN lines and through the CAT Data Link.

Illustration 2	g01822274
Propel System - Machine ECM Machine ECM Connector "J1"

When the main circuit breaker is closed, power transfers from the ECM circuit breaker to the following terminals of machine ECM (1) : "J1-31", "J1-38", "J1-39", "J1-46" and "J1-47". This voltage input provides the power for the processor. When the main power relay is energized, power transfers from the propel fuse to terminal "J1-1" of the machine ECM. This voltage input provides the wake up signal to the machine ECM. The machine ECM is grounded at the following terminals: "J1-13", "J1-23", "J1-56", "J1-57" and "J1-70".

The throttle switch HIGH terminal provides an input to terminal "J1-27" of the machine ECM. If the machine ECM is unable to monitor engine activity through the CAN lines or the Cat Data Link, the ECM will use this input to determine desired engine speed.

Software in the machine ECM analyzes the input signals from machine components. This software determines if an output signal should be sent from the following terminals:

• Terminal "J1-51", When the machines electronic control system determines that the machine should be moving in forward, a pulse width modulated signal is generated from this terminal. The duty cycle of the signal is proportional to the desired travel speed.

• Terminal "J1 52", When the machines electronic control system determines that the machine should be moving in reverse, a pulse width modulated signal is generated from this terminal. The duty cycle of the signal is proportional to the desired travel speed.

• Terminal "J1-58", This terminal energizes the interlock solenoid when the ECM determines that machine conditions are acceptable for normal propel operation. This terminal will be energized when the following conditions are met: the parking brake switch is released, no level three faults are active and the ECM detects no evidence of uncontrolled machine movement. The ECM de-energizes the interlock solenoid when an immediate stop is required of the machine. De-energizing the interlock solenoid releases the valve and purges the propel system charge pressure to the tank.

Terminal "J1-50" of the ECM provides a return path for the forward propel solenoid and for the reverse propel solenoid. Terminal "J1-60" of the ECM provides a return path for the interlock solenoid.

Machine ECM (1) communicates with the engine ECM and with electronic service tools through the Cat Data Link. The Cat Data Link is a proprietary communication standard that was developed by Caterpillar Inc. The Cat Data Link requires a positive line and a negative line. The positive line is connected to terminal "J1-10" of the machine ECM. The negative line is connected to terminal "J1-20" of the machine ECM.

Illustration 3	g01822275
Propel System - Machine ECM Machine ECM Connector "J2"

When the main power relay is energized, power transfers from the propel fuse to terminal "J2-1" of the machine ECM. This voltage input provides power for output signals that is generated by the ECM.

The "R+" terminal of the alternator provides an input to terminal "J2-14" of the machine ECM. This input is used to determine if the engine is running. If the machine ECM is unable to monitor engine activity through the CAN lines or through the Cat Data Link, the ECM will use this input to determine if the engine is running.

Terminal "J2-4" of the ECM provides a return path for the shift solenoid and the backup alarm.

Software in the machine ECM analyzes the input signals from machine components. This software determines if an output signal should be sent from the following terminals:

• Terminal "J2-2", The ECM directs a digital output signal from this terminal when the ECM determines that the shift switch is in the HIGH SPEED position or in the ROADING position. This signal is sent to the shift solenoid.

• Terminal "J2-5", When the ECM determines that the propel lever is in the REVERSE range the ECM generates a pulsed digital output signal from this terminal. These signal pulses are sent to the backup alarm.

• Terminal "J2-6" The ECM directs a digital output signal from this terminal in order to release the parking brake. This signal is sent to the parking brake solenoid.

• Terminal "J2-11", When the ECM determines that a level three fault is active, this terminal is grounded. This ground signal activates the fault alarm.

• Terminal "J2-12", When the ECM determines that a fault is active, the ECM sends a ground signal from this terminal to the fault indicator. When a level one fault is active, the fault indicator will illuminate. When a level two fault or a level three fault is active, the fault indicator will blink. The fault indicator will be active for one second after the machine is activated.

• Terminal "J2-20", When the ECM determines that the propel lever is in the NEUTRAL position, this terminal is grounded. This ground signal activates the neutral indicator.

• Terminal "J2-21" When the ECM determines that the parking brake is engaged, this terminal is grounded. This ground signal activates the parking brake indicator.

The CAN lines provide high speed communication between the machine ECM and the engine ECM. The CAN requires a positive line and a negative line. The positive line is connected to terminal "J2-67" of the machine ECM. The negative line is connected to terminal "J2-68" of the machine ECM.

Illustration 4	g01822276
Rear of Engine (4) Engine ECM (5) Connector "J1" (6) Connector "J2"

Engine ECM (4) is mounted on the rear of the engine. The engine ECM has two 64-pin connectors. Connector "J1" (5) transfers information between the machine harness and the engine ECM. Connector "J2" (6) monitors components which are located on the engine.

Engine ECM (4) monitors engine sensors in order to determine the status of the engine. The engine ECM sends engine information to the machine ECM through the CAN lines and through the Cat Data Link.