621H, 623H and 627H Wheel Tractor-Scrapers Implement Electronic Control System Caterpillar

Component Location Chart : - The component location chart uses white circles as location labels in the machine profile and area views. The alphabetical letters that are in the column for the machine location indicate a general area of the machine. Refer to the corresponding footnote at the end of the chart for a description of the location.

Harness Connector Location Chart: - The "Harness Connector Location" table uses white circles to mark the locations in the general view and in the area views. Alphabetical letters in the "Machine Location" column indicate a general area of the machine. Refer to the footnote at the end of the table for a description of the location.

Implement ECM

Illustration 1	g02607557
Implement ECM location without seat in place.

The Implement ECM is located behind the seat, mounted on the rear wall of the cab, under a molded cover. The Implement ECM is the ECM on the right side and is mounted next to the Chassis/Powertrain ECM.

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Implement ECM with seat in place

Connector Contact Numbers

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Electronic Control Module (ECM)

Illustration 4	g00556522
Machine Harness Connectors J1 and J2 that mate to the ECM.

Cat ET Com Adapter Port

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Communication Adapter Port

The Communication Adapter Port is located in the right rear of the cab, next to the Transmission Shift Lever and Secondary Steering Switch.