292769119-Vmac-III-8-211

SCHEMATICS AND DIAGRAMS SCHEMATICS AND DIAGRAMS Page 717

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SCHEMATICS AND DIAGRAMS SYSTEM CONNECTORS The V-MAC Ј III system utilizes many different connector styles and sizes. The Vehicle Electronic Control Unit (VECU), Engine Electronic Control Unit (EECU), and the Serial Communications Port connectors are the largest connectors in the system, and are where the majority of the V-MAC Ј III system testing is performed. This section illustrates the VECU, EECU, and Serial Communications Port connectors and includes charts with connector terminal identification and functions. The charts should not be used as a replacement for the detailed tests that appear in this manual.

The charts are intended as an identification reference for use when repairing a connector or terminal. 9-Pin Serial Communication Port The Serial Communications Port is a nine (9) pin connector used for system diagnostics and reprogramming. It is located under the dashboard to the left of the steering column. This port is used for connecting a diagnostic computer to the vehicle. See the illustration for the pin locations. A listing of the signal on each pin follows the illustration. 859 6-Pin Serial Communication Port The Serial Communications Port is a six (6) pin connector used for system diagnostics and reprogramming. It is located under the dashboard to the left of the steering column.

This port is used for connecting a diagnostic computer to the vehicle. See the illustration for the pin locations. A listing of the signal on each pin follows the illustration.

858 Figure 859 — 9-Pin Serial Communication Port Figure 858 — 6-Pin Serial Communication Port Page 718 PIN Letter Designation A Serial data link PLUS (+) line B Serial data link MINUS (−) line C PLUS (+) 12 volts D Accessory relay E Chassis ground F Not used PIN Letter Designation A Chassis ground B PLUS (+) 12 volts C J1939 Serial data link PLUS (+) line D J1939 Serial data link MINUS (−) line E J1939 Serial data link shield line F J1587 Serial data link PLUS (+) line G J1587 Serial data link MINUS (−) line H Not used J Not used

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SCHEMATICS AND DIAGRAMS Vehicle Electronic Control Unit (VECU) Connectors VEHICLE ELECTRONIC CONTROL UNIT (VECU) CONNECTOR PIN DESIGNATIONS The Vehicle Electronic Control Unit (VECU) has three 18 pin connectors. Each pin is marked on the inside of the connector. To disconnect a connector from the VECU, press down on the tang of the harness connector and gently pull the connector from the VECU. Be sure that the connector is aligned as shown below to avoid confusion when checking pin numbers. The connector number and color are shown as a reference for reconnecting the VECU to the cab harness.

860 Figure 860 — VECU Connectors Page 719 VECU Connector J1 PIN Number Description 1 Ignition key switch 2 Starter signal 3 Buffered vehicle speed output (Speedometer Signal) 4 Buffered RPM output (Tachometer Signal) 5 Shutdown override signal 6 Speed control ON/OFF switch signal 7 Speed control SET/DECEL signal 8 Speed control RESUME/ACCEL signal 9 Clutch engaged signal 10 Parking brake signal (#1) 11 Service brake signal 12 Engine brake switch — low 13 Engine brake switch — high 14 Not used 15 Fan clutch override 16 Not used 17 Not used 18 Fuel level sensor signal

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SCHEMATICS AND DIAGRAMS Engine Electronic Control Unit (EECU) Connectors (ASET™ IEGR Engine) The Engine Electronic Control Unit (EECU) has two 43 pin connectors. To disconnect a connector from the EECU, pull back on the connector lock and gently pull the connector back on its heel and away from the EECU. For easy reference, the following illustration shows each pin number as it appears on the connector. Be sure that the connector is aligned as shown below to avoid confusion when checking pin numbers. The connector number and EECU orientation are shown as a reference for reconnecting the EECU to the engine harness.

861 Figure 861 — EECU Connectors (ASET™ IEGR Engine) Page 720 VECU Connector J2 PIN Number Description 1 VECU Reference ground 2 Transmission oil temperature signal 3 Front drive axle temperature signal 4 Rear drive axle temperature signal 5 Not used (spare relay) 6 Not used 7 Exhaust temperature sensor signal 8 Exhaust temperature sensor return 9 PTO 1 selected 10 PTO 2 (when selected) 11 Vehicle speed sensor PLUS (+) 12 Vehicle speed sensor MINUS (−) 13 Parking brake signal (#2) 14 Not used 15 Not used 16 Not used 17 CAN-T1 18 CAN-T2 VECU Connector J3 PIN Number Description 1 J1939 data link high 2 J1939 data link low 3 Not used 4 Throttle position sensor voltage reference 5 Throttle position sensor signal 6 Throttle position sensor return 7 Spare relay #3 8 Shutdown lamp (mechanical gauge panel) 9 Electronic Malfunction Lamp (EML) signal (mechanical gauge panel) 10 Spare relay #2 11 Not used (spare driver alarm) 12 Spare relay #1 13 Accessory relay control 14 J1587 serial data link A PLUS (+) 15 J1587 serial data link B MINUS (−) 16 PLUS (+) 12 volts from battery 17 PLUS (+) 12 volts from accessory relay 18 Chassis ground

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