PLATE 8E2898 - Caterpillar

Use this procedure to troubleshoot the data link if a problem is suspected with the data link. Also, use this procedure if one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
CDL Code and Description Conditions which Generate this Code System Response
247-9
SAE J1939 Data Link : Abnormal Update Rate All communications on the data link have been lost. The code is logged.
336-2
Engine Control Switch : Erratic, Intermittent, or Incorrect The Electronic Control Module (ECM) detects an intermittent signal for the engine control switch. The code is logged.
2348-9
SAE J1939 Data Link #2 : Abnormal Update Rate All communications on this data link have been lost. The code is logged.
2853-9
Engine Aftercooler Coolant Temperature Control Module : Abnormal Update Rate All communications between the aftercooler temperature control module and the ECM have been lost. The code is logged.
The aftercooler temperature control module controls the temperature of the aftercooler coolant to the default setpoint.
2854-9
Coolant Temperature Control Module : Abnormal Update Rate All communications between the coolant temperature control module and the ECM have been lost. The code is logged.
The coolant temperature control module controls the temperature of the engine coolant to the default setpoint.
Illustration 1 g02581080
Schematic for the Cat Data Link
Illustration 2 g02580236
Schematic for the local CAN data link (A4 ECM)
Illustration 3 g06320023
Schematic for the local CAN data link (A5 ECM)
Illustration 4 g02725316
Schematic for the global CAN data link 1 (primary ECM)
Illustration 5 g02725346
Schematic for the global CAN data link 2 (secondary ECM)
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
Note: Carefully follow this procedure in order to identify an intermittent problem.
A. Perform a visual inspection of the wiring between the P1 and P2 ECM connectors, the termination resistors, the service tool connector, all of the control box connectors, and the connectors at various controllers.
- Look for these problems:
- Harness damage that is caused by chafing
- Harness damage that is caused by excessive heat
- Look for moisture on the wiring and in the connectors.
- Pull on the wires that are associated with the data links.
This test verifies that the wire is properly crimped to the terminal and that the terminal is properly inserted into the connector.
Connectors
Results: The wiring and the connectors appear to be OK.
Proceed to Test Step 2
Results: There is a problem with the wiring or with a connector.
Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the connector seals are properly in place and ensure that the connectors are coupled. Verify that the problem is resolved.
2. Bypass the Wiring for the Data Link
A. Connect the 217-0113 Wiring Harness (ECM BYPASS) to the J1 connector, to the 332-7381 Data Link Cable As, and to the battery.
B. Try to establish communication between Cat ET and the ECM.
Data link
Results: Cat ET and the ECM communicate.
Repair Cat ET and the ECM communicate when the bypass harness is installed. However, communication cannot be established via the engine wiring.
Disconnect the electrical connector from each of the control modules that is on the data link one