If the Caterpillar Electronic Technician (ET) will not communicate with the ECM, refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" before you begin this procedure. The procedure verifies that electrical power is being supplied to the ECM and to the service tool connector.
The data links are used to communicate information between the engine ECM and other control modules that are a part of the application. Cat ET also communicates with the ECM via the data links.
The service tool connector contains connections for electrical power and for the data links.
| Diagnostic Codes | |||
| Code | Description | Conditions | Notes |
| 523547-2 | CAN Data Link: Error, Intermittent, or Incorrect | Battery voltage is normal | Low Idle only |
| 523548-2 | CAN Data Link: Error, Intermittent, or Incorrect | Battery voltage is normal | Low Idle only |
| 523591-2 | CAN Data Link: Error, Intermittent, or Incorrect | Battery voltage is normal. No Start switch signal. |
CAN Frame time error. Engine ECU assumes that parking switch is Off and Vehicle Speed is 0. |
| 523592-2 | CAN Data Link: Error, Intermittent, or Incorrect | CAN Frame time error. Regeneration is Inhibited. Parked Regeneration is Inhibited. |
|
| 523593-2 | CAN Data Link: Error, Intermittent, or Incorrect | CAN Frame time error. | |
| 523594-2 | CAN Data Link: Error, Intermittent, or Incorrect | CAN Frame time error. | |
| 523595-2 | CAN Data Link: Error, Intermittent, or Incorrect | CAN Frame time error. | |
| 523596–2 | CAN TSC1 Frame Error | CAN Frame time error. | |
| 523598–2 | CAN EBC1 Frame Error | CAN Frame time error. Engine derated |
|
| 523604-2 | CAN1 Bus Off | Key switch is ON. Battery voltage is normal. |
CAN1 Bus +B or Ground Open Circuit or high traffic error for 2 seconds or more. EGR Stop Engine derated Warning Level 3 |
Note: When the machine ECM is flashed, any of the codes will be active. The code is logged after the key switch is cycled. To clear the codes, turn the key switch to the ON position.
If the codes are active, they are indicating a harness issue.
Code 523604-2 is indicating a harness issue in the wires for CAN communication between the engine ECM “Pins 13 and 43 on machine connector side” and to either the service tool or to the NRS Valve. Check the harness and the connectors in this circuit.
The remaining codes are indicating a harness issue in the CAN communication between the engine ECM and the machine ECM “Pin 30 and 42 on machine connector side”. Check the harness and the connectors in this circuit.