SADDLE AS-SUPPORT 4V6156 - Caterpillar

Illustration 1 g02345544
The Transmission ECU electronically interrelates with the following functions, sensors, inputs, and outputs:
OEM Components
Transmission Monitoring Lamps
Torque Converter Outlet Sensors
Transmission Sump Temperature Sensors
Transmission Filter Bypass Switch
Converter Output Sensors
Transmission Speed Sensors
Oil Level Sensor
Transmission Shift Points
Neutral Start Function
Parking Brake
Torque LimitingGeneral Operation
The CX28 transmission with 455/484 transfer case is a special application product with special transmission software and wiring harness.This arrangement is used in 2 and 3 drive axle vehicle applications with full time all wheel drive. The Transfer Case has two speeds and provides differential locking between front and rear axles. Separate ECM inputs and outputs control wheel to wheel (same axle) locking on rear and front axles. There are no electrical differences between the 455 and 484 transfer cases.Operation of the differential to differential lock is operator controlled with the shift pad Mode Button. On 6x6 vehicles, the rear inter-axle differential lock will be enabled or disabled with the front to rear differential lock. The low and high ranges of the transfer case are controlled by a chassis mounted switch input. The front axle side to side wheel lock and the rear axle side to side wheel locks are requested with chassis mounted switch inputs.The ECU provides the service technician with enhanced diagnostic capabilities. This is available by using onboard memory. Onboard memory stores the possible diagnostic trouble codes for retrieval at the time of service. Service personnel should use the Caterpillar Electronic Technician (ET) for troubleshooting.The following electronic control modules communicate with each other through the J1939 data link: Engine, Transmission, Anti-lock Brake, and Traction Control Systems (if equipped). These modules share internal information and may temporarily control other modules that are connected to the data link. Other devices connected to the data link, such as an instrument cluster, can display information that is broadcast over the data link. Other devices may use the data link in order to broadcast the positions of switches. The service brake and the parking brake are examples of switch information that can be based on the data link.Overview
There are no sensor outputs that are accessible to the customer. All sensor outputs are only available over the J1939 or the J1587 data link.Transmission ECU
The ECU is located on the top left of the transmission. The ECU is controlled by software that is developed by Caterpillar for this transmission.Shift Selector
The transmission shift selector is a J1939 device on the data link that communicates the preferences of the operator to the Transmission ECU. The shift selector has a display that indicates the current gear. The display also functions as an indicator for tasks that are related to service.Temperature Sensors
The ECU monitors the temperature of the torque converter oil at the outlet. The ECU also monitors the temperature of the transmission oil in the sump.Oil Level Sensor
The oil level sensor is used in order to check the level of the oil in the transmission. The operator may initiate this check with the controls that are on the shift selector. The ECU takes no action if the