caterpillar engine rebuilders

Systems Operation
69D, 769D, 771D, 773D, 773E, 775D, 775E, 776D, 777D, 784C, 785C, 789C, 793C XQ
and 793C Off-Highway Truck/Tractors Brake Electronic Control System
Electronic Control Module (ECM)
SMCS - 7610-BRK
S/N - 1HW1-UP
S/N - 2BW1-658
S/N - 2PZ1-105
S/N - 4GZ1-UP
S/N - 5AZ1-399
S/N - APX1-450
S/N - ATY1-UP
S/N - CBR1-UP
Shutdown SIS
Previous Screen
Product: TRUCK
Model: 785C TRUCK APX
Configuration: 785C Off-Highway Truck APX00001-UP (MACHINE)
POWERED BY 3512B Engine
Media Number -SENR1503-08 Publication Date -01/08/2004 Date Updated -23/08/2004
i01662218
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The brake ECM will make decisions that are based on information from each input and information
from memory. After the brake ECM receives the information from each input and information from
memory, the brake ECM will send a corresponding response through the outputs. Each input and
each output of the brake ECM connects to the machine harness by two 40-pin connectors (J1 and J2).
Inputs
The machine has several input devices. The brake ECM receives information from components
about machine operations. The machine utilizes the following inputs: switch type and sensor type.
Switches provide signals to the switch inputs of the ECM. The possible outputs of a switch are listed:
an open signal, a grounded signal and + battery signal.
Sensors provide a signal to the ECM that constantly changes. Each input to the brake ECM is listed
in the two tables for the 40-pin connector.
Outputs
The brake ECM sends electrical signals through the outputs. The outputs can create an action or the
outputs can provide information to the brake ECM. The outputs for the brake ECM are listed in the
two tables for the 40-pin connector.
Input/Output
Each ECM uses the CAT data link to communicate with each other. The data link is bidirectional.
The data link allows the ECM to receive information. The data link allows the ECM to send
information. The data link allows the sharing of information with other electronic control modules.
Illustration 1 g00330892
Electronic Control Module (ECM)
(1) Connector J1. (2) Connector J2.
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A module identifier (MID) is assigned to each ECM. The MID for the brake ECM is the number
116.
Table 1
Contact Description For J1 Of The Brake ECM (1)
No. Function Type
1 Key Start Switch Power
2 Ground Ground
3 Cat Data Link - Input/Output
4 Retarder Lamp Output
5 Ground Ground
6 Key Start Switch Power
7 Solenoid Return Output Return
8 TCS Dash Lamp Output
9 CAT Data Link + Input/Output
10 TCS Right Brake Solenoid Solenoid Output
11 TCS Left Brake Solenoid Solenoid Output
12 ARC Solenoid Solenoid Output
13 ARC ON/OFF Switch Switch Input
14 ARC ON/OFF Switch Switch Input
15 SW And Sensor Ground Ground
16 SW And Sensor Ground Ground
17 TCS Proportional Servo Valve Solenoid Output
18 ARC Supply Solenoid Solenoid Output (ON/OFF)
19 TCS Test Switch Switch Input
20 ARC Pressure Switch Switch Input
21 Location Code 1 (ground) Switch Input
22 Location Code 0 (open) Switch Input
23 Retarder Switch Switch Input
25 Oil Filter Switch for the Brake Cooling System Switch Input
26 Brake Overstroke Switch Switch Input
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28 ECM Location Enable (+battery) Switch To Battery
30 (2) Filter Bypass Switch Switch Input
31 Level Switch for the Rear Differential Switch Input
32 Oil Filter Switch for the Rear Differential Switch Input
33 Oil Filter Switch for the Parking Brake Switch Input
38 Location Code 2 (Open) Switch Input
40 Key Start Switch Switch Input
( 1 ) The connector contacts that are not listed are not used. The connector has 40 contacts.
( 2 ) This connector contact is an optional attachment.
Table 2
Contact Description For J2 Of The Brake ECM (1)
No. Function Type
1 HI Solenoid for the Rear Fan Solenoid Output
3 Solenoid Return Output Return
4 Pressure Sensor for the Left Brake Sensor Input
5 Pressure Sensor for the Right Brake Sensor Input
6 Pressure Sensor for the Rear Differential Oil Switch Input
10 Temperature Sensor for the Rear Differential Oil Switch Input
11 Brake System Air Pressure Sensor Switch Input
12 +8 V Sensor Supply Output
14 (2) Fan Speed Sensor for Left Radiator Sensor Input
15 +10 V Sensor Supply +10 V Sensor Power Supply
18 (2) Hydraulic Oil Temperature Sensor Sensor Input
19 (2) Cooling Fan Solenoid for the Hydraulic Oil Solenoid Output
23 Right Rear Wheel Speed Sensor Sensor Input
31 (2) Fan Speed Sensor for Right Radiator Sensor Input
35 Engine Speed Sensor Sensor Input
37 Lo Solenoid for the Rear Fan Output
38 Left Rear Wheel Speed Sensor Sensor Input
( 1 ) The connector contacts that are not listed are not used. The connector has 40 contacts.
( 2 ) This connector contact is an optional attachment.
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