GASKET 2S2984 - Caterpillar

diagnostic code is recorded when the ECM does not receive expected information or faulty information is detected. The CAT data link is used to communicate between the ECM and the controllers. The CAT data link circuit of the machine harness consists of the following components:
The + CAT data link is wire 883-GY (J1-9).
The - CAT data link is wire 882-PK (J1-3). The possible causes of this diagnostic code are listed here:
There is a poor electrical connection at a machine harness connector.
The CAT data link circuit in the machine harness is shorted to ground.
The CAT data link circuit in the machine harness is shorted to +battery.
The CAT data link circuit in the machine harness is open.
One of the controllers that is using the CAT data link is faulty. This is unlikely.
The ECM is faulty. This is unlikely. The system response to this level three diagnostic code is listed below:
The diagnostic code indicator flashes.
The alarm beeps.
The readouts show the word "FAULT".
The elevation of the machine cannot be changed. Note: The ECM uses the CAT data link to control both readouts and all indicators on each controller. Therefore, the responses of the system that are listed above may not be visible. Use the following procedures to service a suspected CAT data link fault. Note: The Grade & Slope Electronic Control System and the Computerized Profiler Control System have separate CAT data links.
Inspect Harness Connectors.
Turn the disconnect switch to the OFF position.
Inspect the machine harness connectors at the ECM.
Inspect the machine harness connectors at all six locations for a controller. Do the inspection even if a controller is not used at one of the locations.
Inspect the service connector for the Grade & Slope Electronic Control System.
Make sure that the connectors are clean and tight. Expected Result: The connectors are clean and tight. Results:
Yes - Proceed to 2.
No - Repair or if necessary replace the machine harness. STOP.
Check Harness For Short To Ground.
The disconnect switch remains OFF.
Disconnect the machine harness from the ECM and from all the controllers.
At the machine harness connector for the ECM, measure the resistance from contact J1-3 (882-PK) to frame ground.
At the machine harness connector for the ECM, measure the resistance from contact J1-9 (883-GY) to frame ground. Expected Result: The resistance