Using Caterpillar Electronic Technician (Cat ET) to Determine Diagnostic Trouble Codes
Connect the Caterpillar Electronic Technician (Cat ET) to the machine. Turn the key start switch to the RUN position. Start the Cat ET. The Cat ET will initiate communications with the Electronic Control Modules on the machine. After communication has been established, the Cat ET will list the Electronic Control Modules. Choose the desired Electronic Control Module. After the diagnostic trouble codes have been determined with the Cat ET, see the test procedure for the corresponding diagnostic trouble code.
Reference: Troubleshooting, "Service Tools"
Active Diagnostic Trouble Codes
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Typical Cat ET screen for active diagnostic trouble codes | |
The following procedures may cause new diagnostic trouble codes to be logged. Therefore, before any procedures are performed, make a list of all the active diagnostic trouble codes in order to determine the system problems. Clear the diagnostic trouble codes that were caused by the procedure, when each procedure is complete.
Note: Before performing a procedure, always check all the circuit breakers. Repair the cause of any circuit breaker that is tripped.
A screen is provided in Cat ET for active diagnostic trouble codes. The screen will display the diagnostic trouble codes that are active. Active diagnostic information shall include a component identifier (CID), a failure mode identifier (FMI) and a text description of the problem.
Logged Diagnostic Trouble Codes
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Typical Cat ET screen for logged diagnostic trouble codes | |
A screen is provided in Cat ET for logged diagnostic trouble codes. The screen will display diagnostic trouble codes that are logged. The Cat ET will log diagnostic trouble codes that are intermittent. The logged diagnostic data shall include a CID, an FMI, and a text description of the problem. Also, the logged diagnostic data shall include the number of occurrences of the problem and two time stamps. The time stamp displays the first occurrence of the problem and the time stamp displays the most recent occurrence of the problem.
Diagnostics are logged in non-volatile memory. On powerup, the ECU will clear any diagnostic trouble codes that have not been detected or active within the last 150 hours of machine operation.