- An invalid signal from an input
- An improper feedback from an output
- An internal error
Accessing Diagnostic Codes
Diagnostic information can be accessed with:
- Cat® Electronic Technician (Cat ET).
- Advisor
Note: Before performing a test procedure, always check all the circuit breakers. Repair the cause of any circuit breaker that is tripped.
Note: Test procedures may cause new diagnostic trouble codes to be logged. Defore any procedures are performed, make a list of all the active diagnostic trouble codes. Clear the diagnostic trouble codes that were caused by the procedure, after each procedure is complete.
Accessing With Cat® Electronic Technician (Cat ET)
Cat ET can be used to access diagnostic codes. The component identifier (CID) identifies the specific component and the failure mode identifier (FMI) identifies the type of diagnostic detected. The service tool displays the CID-FMI with descriptive text for each combination to help avoid mistakes in interpreting the codes.
To access the codes:
- Connect Cat ET to the machine.
- Turn on the key start switch
- Start Cat ET.
Cat ET will initiate communications with the electronic control modules (ECMs) on the machine. After communication has been established, Cat ET will list the ECMs.
- Choose the desired ECM.
Cat ET will list the codes.
- See the test procedure for the code.
Reference Troubleshooting, "Service Tools"
Diagnostic trouble codes can be:
- Active
- Logged
Active Diagnostic Trouble Codes
Illustration 1 | g02732497 |
Typical Cat ET active diagnostic trouble code screen |
An active diagnostic trouble code screen is provided in Cat ET. Active diagnostic information includes:
- Component identifier (CID)
- Failure mode identifier (FMI)
- Text description of the problem
Logged Diagnostic Trouble Codes
Illustration 2 | g02732498 |
Typical Cat ET logged diagnostic trouble code screen |
A logged diagnostic trouble code screen is provided in Cat ET. Cat ET logs diagnostic trouble codes that are intermittent. The logged diagnostic data includes:
- CID
- FMI
- Text description of the problem
- Number of occurrences of the problem
- Time stamp of the first occurrence of the problem
- Time stamp of the most recent occurrence of the problem
Diagnostics are logged in non-volatile memory. On power-up, the ECM will clear any diagnostic trouble codes that have not been detected or active within the last 150 hours of machine operation.
Accessing With Advisor
Illustration 3 | g02850456 |
Typical Advisor screen for accessing diagnostics |
Perform the following to access the diagnostics screen from the service menu:
- Use the appropriate arrow button to highlight the "Diagnostics" option.
- Press the buttons on the RH side to access the diagnostics screen.
- Select "Active Events" to show a list of active diagnostics.
Illustration 4 | g02727932 |
Typical active diagnostic screen |
- Select "Logged Events" to show a list of logged diagnostic codes.
Illustration 5 | g02727933 |
Typical logged diagnostic screen |
Each line in each list shows the following:
- Component description
- Warning level
Perform the following to access the codes and events from the diagnostics screen:
- Use the appropriate arrow button to highlight a specific code (line on the list).
- Press the RH button to display the detailed view of that line.
The detailed view will display a text message. The text message will include the following:
- The reporting ECM (MID)
- Identity of the component that has failed (CID)
- Failure Mode Identifier (FMI)
- An explanation of the failure
- Number of active or logged events
- A description of the component causing the fault
- The fact that the code is currently active or logged
Note: The codes and the events that are displayed in the diagnostics option may be viewed at any time. Logged codes can be cleared with the Cat ET.
Active Diagnostics
If the Cat service tool is available, the service tool can display all active and logged diagnostic codes.
Logged Diagnostics
Logged diagnostics:
- Record intermittent problems
- Eliminate the need to duplicate intermittent problems
- Increase diagnosis accuracy
- Reduce troubleshooting time
- Eliminate the need for trip recorders to capture intermittent diagnostic information
The ECM memory is used to store diagnostic information. When a diagnostic is detected, the following information is logged:
- The CID will identify the component that has failed
- The FMI will describe the problem
- Number of occurrences of the diagnostic code
- The time of the first occurrence that the diagnostic was detected
- Last occurrence time, when the diagnostic was last detected (stored with both machine hours and RTC stamp)
The ECM logs the number of times that the machine is started using an unauthorized method.
Reference Machine Troubleshooting, "Diagnostic Trouble Codes" manual