777F Off-Highway Truck Power Train: Machine Electronic Control Module (Chassis)

Chassis Electronic Control Module (ECM)(1) Connector J1. (2) Connector J2.

The chassis electronic control module (ECM) is located on the back wall of the cab to the right of the operator's station. The chassis ECM shifts the transmission. The operator input indicates the desired speed for the transmission and the desired direction for the transmission. The chassis ECM makes decisions that are based on the input information and on the memory information. After the chassis ECM receives the input information and the memory information, the chassis ECM sends a corresponding response via the outputs. The inputs and outputs of the chassis ECM are connected to the machine harness. Use contact connectors J1 and J2.

Inputs

The machine has several input devices. Input devices inform the chassis ECM of the operating conditions of the machine. The machine has inputs from switches and sensors. Switches provide an open, a ground or a +battery to the inputs of the implement ECM. Sensors provide a constantly changing signal to the chassis ECM. The inputs into the implement ECM are listed in the tables that follow.

Outputs

The chassis ECM responds to decisions by sending electrical signals through the outputs. The outputs can create an action or the outputs can provide information to the chassis ECM. The outputs for the implement ECM are listed in the tables that follow.

Input/Output

The CAT Data Link is used to communicate with the other electronic control modules on the machine. The CAT Data Link is bidirectional. This allows the chassis ECM to receive information and this allows the chassis ECM to send information. The CAT Data Link allows the sharing of information with other electronic controls.

A module identifier (MID) is assigned to all of the electronic controls that use the CAT Data Link. The MID for the chassis ECM is 081.

Torque Limiting

The 775F has a torque limiting feature that protects the power train system from excessive torque loads. This action is accomplished during stall conditions. If the torque converter is stalled with the machine in the First gear or the machine in the Reverse gear, the chassis ECM will instruct the engine ECM to limit the engine speed to 1831 ± 65 rpm. The stall rpm for the torque converter without torque limiting is 1922 ± 65 rpm.

The torque can be measured by using the transmission stall test in the messenger and the advisor. Refer to Service Manual, RENR8344, "Transmission Stall Test" for instructions on performing a transmission stall test.

MARYGAR

777F Off-Highway Truck Power Train: Machine Electronic Control Module (Chassis) 2012-12-16T10:11:00-08:00 Rating: 4.5 Diposkan Oleh: Unknown