FILM-INSTRUCTION 1307492 - Caterpillar

Illustration 1 g02112358
Schematic for the Cat Data Link and the CAN data link
Illustration 2 g01672679
Terminal locations at the service tool connector (A) +Battery (B) −Battery (C) CAN shield (D) Cat Data Link + (E) Cat Data Link − (F) CAN data link − (G) CAN data link +
Illustration 3 g01672676
Terminal locations at the P1 ECM connector that are for the data link (P1-8) Cat Data Link + (P1-9) Cat Data Link − (P1-34) CAN data link − (P1-42) CAN shield (P1-48) +Battery (if applicable) (P1-50) CAN data link + (P1-52) +Battery (if applicable) (P1-53) +Battery (if applicable) (P1-61) −Battery (if applicable) (P1-63) −Battery (if applicable) (P1-65) −Battery (if applicable) (P1-70) Keyswitch
Illustration 4 g02078636
P2 ECM connector (P2-11) CAN data link − (P2-12) CAN data link +
Table 2
Resistance Measurements for the Cat Data Link    
Connector and Terminal    Terminal    
P1-8 (Cat Data Link +)     All of the other terminals on the P1 connector    
Negative ground
P1-9 (Cat Data Link -)     All of the other terminals on the P1 connector    
Negative ground
P1-50 (CAN data link +)     All of the other terminals on the P1 connector    
Negative ground
P1-34 (CAN data link -)     All of the other terminals on the P1 connector    
Negative ground
P2-12 (CAN data link +)     All of the other terminals on the P2 connector    
Negative ground
P2-11 (CAN data link -)     All of the other terminals on the P2 connector    
Negative ground
Table 3
Troubleshooting Test Steps    Values    Results    
1. Check for a Short Circuit
A. Turn the keyswitch to the OFF position.
B. Thoroughly inspect the connectors that are associated with the data link circuits. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Disconnect the P1 and the P2 ECM connector.
D. Disconnect Cat ET from the service tool connector.
E. Measure the resistance between the points that are listed in Table 2. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
   
Open circuit    
Result: Each check of the resistance indicates an open circuit.
Proceed to Test Step 2
Result: At least one check of the resistance does not indicate an open circuit. There is a short circuit in the harness or in a connector.
Repair the connectors and/or the wiring. Replace parts, if necessary. Verify that the original problem is resolved.
   
2. Check for an Open Circuit
A. Fabricate a jumper wire that is long