ENGINE ARRANGEMENT 9N6202 - Caterpillar

Illustration 1 g03399569
Traction Control subsystem schematic
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735B/740B machinesDiagram of the Chassis ECMThe Chassis ECM electronically controls the following functions:
Tractive performance of machines, known as the Automatic Traction Control (ATC) feature
ATC fault detection and reportingATC measures and monitors multiple inputs. This information is converted into a solution that is used to obtain the best tractive efficiency in given conditions.The benefits of ATC are:
Reduced cycle time
Reduced tire wear
Reduced fuel consumption
Potential increase in component life, particularly for the lower power train
Reduced operator skill level required
Reduced operator workload
Safety benefits dependent on operating conditions and operator skill Overview
The following components used in the ATC system (with descriptions) are as follows:
Speed Sensors Two speed sensors are on each axle with a total of six speed sensors on the ATC system. These speed sensors are located on each differential gear cover. The speed sensors on the system measure the differential case speed or the axle speed. The differential case speed is the average of the left and the right axle speed. The axle speed is used to calculate wheel speed, which the ATC feature uses to prevent wheel slip. If the sensor does not detect target rotation, a special pulse is sent to the ECM. This pulse can be used for zero motion detection and diagnostic purposes.
Inertial Measurement Sensor One inertial measurement sensor is on the ATC system. The sensor measures longitudinal acceleration, lateral acceleration, vertical acceleration, and yaw rate. The sensor is located underneath the cab, directly above the front axle.
Inter Axle Lock Accumulator Pressure One inter axle lock accumulator pressure sensor is on the ATC system. The sensor measures the pressure at the inter axle lock accumulator. The sensor is located on the top of the Output Transfer Gear (OTG) valve.
Inter Axle and Cross Axle Lock Solenoids Four proportional solenoids are on the ATC system. Three proportional solenoids control the cross axle lock clutch by managing the speed deviation of the left and the right wheel of each axle. These cross axle solenoids are located above each axle. One proportional solenoid is used to control the inter axle lock clutch by managing the speed deviation from the front and the rear of the machine. The inter axle solenoid is located on top of the OTG valve.
Inter Axle Lock Accumulator Charge Solenoid One ON/OFF solenoid is on the ATC system. This charge solenoid charges the OTG accumulator, which is used to supplement inter axle lock solenoid.The Chassis ECM also monitors:
The inputs and outputs component status
The communication status between ECMs
The operating system statusIf the Chassis ECM detects a problem, a diagnostic trouble code (DTC) will activate and display on CAT Electronic Technician (Cat ET.) and the Caterpillar Multi-Purpose Display (CMPD) via CAT Datalink (CDL) or CAN J1939 Datalink. Note: For a complete list of codes refer to the Diagnostic Code List and Event Code List sections of this book.