Product Link – PL522/523 – System Components

Electronic Control Module (ECM)

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PL522 and 523 ECM

The PL522 and 523 are electronic control modules (ECM). The ECM is initially setup by using a laptop computer with the Caterpillar Electronic Technician (Cat ET ) software. In order to use the new PL522 and 523 features, update to the latest version of Cat ET. Refer to Special Instruction, REHS2368 for more information on installing the PL522 and the 523.

Ensure that the PL522 and 523 modules are installed with the available shock mount kit. All machines require shock mounting.


The PL522 and 523 can be set up to receive information from components about machine operations by using switch-to-ground type inputs. Switches provide ON or OFF (closed or open) signals to the switch inputs of the PL522 and 523. The inputs to the PL522 and 523 are listed in the table for the 70 pin connector.


The PL522 and 523 use the Cat Data Link in order to communicate with other electronic control modules. The Cat Data Link is bidirectional. The data link allows the PL522 and 523 to receive information. The Cat Data Link also allows the PL522 and 523 to send information.

A module identifier (MID) is assigned to each ECM. The MID for the PL522 and 523 is 161.

Table 1
Product Link Contact Description    
Contact Number     Function     Type    
34     CAN Low     Input    
50     CAN High     Input    
42     CAN Shield     Input    
52     + Battery     Power    
65     Ground     Ground    
54     Alternator R -Terminal     Input    
70     Key switch     Input    
8     Cat Data Link +     Input/Output    
9     Cat Data Link –     Input/Output    
45     Spare Digital Input 1     Switch Input (Open/Ground)    
46     Spare Digital Input 2     Switch Input (Open/Ground)    
47     Spare Digital Input 3     Switch Input (Open/Ground)    
55     Spare Digital Input 4     Switch Input (Open/Ground)    

Adapter Plates

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PL522 and 523 ECM Adapter Plates

The adapter plates allow a dealer to mount a PL522 or 523 in a place originally planned for a PL151/PL201.

Wiring Harnesses

The installation kit includes the control harness assembly. The wiring harness is enclosed in a protective braided cover.

ECM Harness

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(4) 12 pin receptacle connector (J1)

(5) 70 socket plug connector (P1)

(6) 12 socket plug connector (P2)

(7) 2 socket plug connector (P3)