JOINT-BALL 3208569 - Caterpillar

Table 1
Diagnostic Trouble Codes for the CAN Data Link Circuit
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
639-9 247-9 J1939 Network #1 : Abnormal Update Rate Another controller has incorrectly stopped transmitting an expected J1939 message or another controller has incorrectly started transmitting a conflicting J1939 message.
The ECM will log the diagnostic code.
The engine will not start.
1196-2 1639-2 Anti-theft Component Status States : Erratic, Intermittent, or Incorrect The Electronic Control Module (ECM) detects poor communications with the Machine Security System (MSS).
The engine warning lamp will come on and the ECM will log the diagnostic code.
The engine will not start.
1196-9 1639-9 Anti-theft Component Status States : Special Instruction The Electronic Control Module (ECM) detects a loss of communications with the Machine Security System (MSS).
The warning lamp will come on and the ECM will log the diagnostic code.
The engine will not start.
1235-9 5856-9 J1939 Network #3 : Abnormal Update Rate The Pump and Electronics Unit (PEU), the ammonia sensor, the soot sensor, or a NOx sensor has incorrectly stopped or started transmitting a data request.
This diagnostic code applies to the CAN C datalink
The ECM will log the diagnostic code.
3360-9 3820-9 Aftertreatment #1 DEF Controller : Abnormal Update Rate The Dosing Control Unit (DCU) has incorrectly stopped or started transmitting a data request.
This diagnostic code applies to the CAN A datalink.
The ECM will log the diagnostic code. The following background information is related to this procedure:The CAN data links are also known as J1939 data links. A data link is an industry standard for sending data between different devices in the same application.High-speed data is transferred via the data links. The data links cannot be accurately tested without complicated equipment. The data links require a resistance of 60 Ohms between the two wires to transmit the data correctly. This resistance is made up of two 120 Ohm resistors. The two resistors are known as "Terminating Resistors". The terminating resistors should be at opposite ends of a data link circuit. If this resistance is not present, then the data will be intermittent or unreadable.Note: The wiring for a J1939 data link is a shielded twisted-pair cable. If the wiring is damaged, the replacement type must be shielded twisted-pair cable.
Illustration 1 g03705249
Typical example of the schematic for the CAN A data link
Illustration 2 g03705266
Typical example of the schematic for the CAN C data link
Table 2
Troubleshooting Test Steps Values Results
1. Use the "System Communication Status to Check the Status of the Other Devices on the Suspect CAN Data Link"
A. In the electronic service tool, click the "Diagnostics" tab on the tool bar.
B. Select the "System Communication Status" option from the drop-down list.
Note: The Aftertreatment #1 Intake NOx Level Sensor is displayed as Aftertreatment #1 Information #1 in some versions of software.
Component Identified
Result: One or more of the devices on the suspect data link is not visible on the electronic service tool.
Repair: Thoroughly inspect the electrical connectors for the suspect devices
Refer