Using the Caterpillar Electronic Technician (Cat ET) to Determine Diagnostic 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 codes have been determined with the Cat ET, see the test procedure for the corresponding diagnostic code.
Reference: Troubleshooting, "Service Tools"
Active Diagnostic Codes
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Typical Cat ET screen for active diagnostic codes | |
The following procedures may cause new diagnostic codes to be logged. Therefore, before any procedures are performed make a list of all the active diagnostic codes in order to determine the system problems. Clear the diagnostic 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 codes. The screen will display the diagnostic 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 Codes
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Typical Cat ET screen for logged diagnostic codes | |
A screen is provided in Cat ET for logged diagnostic codes. The screen will display diagnostic codes that are logged. The Cat ET will log diagnostic codes that are intermittent. The logged diagnostic data shall include a CID, a 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 codes that have not been detected or active within the last 150 hours of machine operation.