Diagnostic Codes
Diagnostic codes alert the operator that a problem in the electronic system has been detected. Diagnostic codes also indicate the nature of the problem to the service technician. The Caterpillar Electronic Technician (ET) is a software program that is designed to run on a personal computer. Diagnostic codes may be viewed on a personal computer that has Cat ET software. Diagnostic codes consist of the component identifier (CID) and the failure mode identifier (FMI).
Component Identifier (CID) - The CID is a number with three or four digits. The CID indicates the component that generated the code. For example, the CID number 0001 identifies the fuel injector for the number one cylinder.
Failure Mode Identifier (FMI) - The FMI is a two digit code that indicates the type of failure.
Do not confuse diagnostic codes with event codes. Event codes alert the operator that an abnormal operating condition such as low oil pressure or high coolant temperature has been detected. Refer to Troubleshooting, "Troubleshooting with an Event Code" for additional information on event codes.
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| Illustration 1 | g01117578 |
Output voltage from a typical analog temperature sensor | |
Illustration 1 indicates the signal range for a typical analog sensor. Diagnostic codes will be generated if the sensor's output signal is below 0.2 VDC or above 4.8 VDC.
Active Diagnostic Codes
An active diagnostic code represents a problem with the electronic control system. Correct the problem as soon as possible.
When the ECM generates an active diagnostic code, the "Active Alarm" indicator ("Engine Control Alarm Status" on Cat ET) is activated in order to alert the operator. If the condition that generated the code is momentary, the message disappears from the list of active diagnostic codes. The diagnostic code becomes logged.
Logged Diagnostic Codes
When the ECM generates a diagnostic code, the ECM logs the code in permanent memory. The ECM has an internal diagnostic clock. Each ECM will record the following information when a code is generated:
- The hour of the first occurrence of the code
- The hour of the last occurrence of the code
- The number of occurrences of the code
This information is a valuable indicator for troubleshooting intermittent problems.
A code is cleared from memory when one of the following conditions occur:
- The service technician manually clears the code.
- The code does not recur for 100 hours.
- A new code is logged and there are already ten codes in memory. In this case, the oldest code is cleared.
Some diagnostic codes may be easily triggered. Some diagnostic codes may log occurrences that did not result in complaints. The most likely cause of an intermittent problem is a faulty connection or damaged wiring. The next likely cause is a component failure. The least likely cause is the failure of an electronic module. Diagnostic codes that are logged repeatedly may indicate a problem that needs special investigation.
Note: Always clear logged diagnostic codes after investigating and correcting the problem which generated the code.
Cross-Reference for SPN-FMI Code to CID-FMI (Diagnostics)
| Cross-Reference for SPN-FMI Code to CID-FMI (Diagnostics) | ||
|---|---|---|
| SPN/FMI Code | CID-FMI or EID | Description of Code |
| 651-11 | 1-11 | Injector Cylinder #1 fault |
| 652-11 | 2-11 | Injector Cylinder #2 fault |
| 653-11 | 3-11 | Injector Cylinder #3 fault |
| 654-11 | 4-11 | Injector Cylinder #4 fault |
| 655-11 | 5-11 | Injector Cylinder #5 fault |
| 656-11 | 6-11 | Injector Cylinder #6 fault |
| 678-03 | 41-03 | Digital Sensor Supply short to +batt |
| 678-04 | 41-04 | Digital Sensor Supply short to ground |
| 679-05 | 42-05 | Inject Actuation Control Valve open circuit |
| 679-06 | 42-06 | Inject Actuation Control Valve short |
| 679-08 | 42-08 | Inject Actuation Control Valve pulse width abnormal |
| 91-08 | 91-08 | Throttle Position signal abnormal |
| 94-03 | 94-03 | Fuel Pressure open/short to +batt |
| 94-04 | 94-04 | Fuel Pressure short to ground |
| 100-03 | 100-03 | Engine Oil Pressure open/short to +batt |
| 100-04 | 100-04 | Engine Oil Pressure short to ground |
| 100-10 | 100-10 | Engine Oil Pressure abnormal rate of change |
| 102-03 | 102-03 | Boost Pressure Sensor open/short to +batt |
| 102-04 | 102-04 | Boost Pressure Sensor short to ground |
| 110-03 | 110-03 | Engine Coolant Temperature open/short to +batt |
| 110-04 | 110-04 | Engine Coolant Temperature short to ground |
| 108-03 | 274-03 | Atmospheric Temperature Sensor open/short to +batt |
| 108-04 | 274-04 | Atmospheric Temperature Sensor short to ground |
| 164-00 | 164-00 | High Injector Actuation Pressure |
| 164-01 | 164-01 | Low Injector Actuation Pressure |
| 164-03 | 164-03 | Injector Actuation Pressure open/short to +batt |
| 164-04 | 164-04 | Injector Actuation Pressure short to ground |
| 168-15 | 168-00 | System Voltage High |
| 168-01 | 168-01 | System Voltage Low |
| 168-02 | 168-02 | System Voltage intermittent/erratic |
| 105-03 | 172-03 | Inlet Manifold Temp Sensor open/short to +batt |
| 105-04 | 172-04 | Inlet Manifold Temp Sensor short to ground |
| 174-03 | 174-03 | Fuel Temperature open/short to +batt |
| 174-04 | 174-04 | Fuel Temperature short to ground |
| 190-08 | 190-08 | Engine Speed Signal Abnormal |
| 234-11 | 253-11 | Personality Module mismatch |
| 228-11 | 261-11 | Engine Timing fault |
| 228-13 | 261-13 | Engine Timing calibration required |
| 620-03 | 262-03 | 5 Volt Sensor DC Power Supply short to +batt |
| 620-04 | 262-04 | 5 Volt Sensor DC Power Supply short to ground |
| 1111-02 | 268-02 | Check Programmable Parameters |
| 1080-03 | 269-03 | Check Programmable Parameters |
| 1080-04 | 269-04 | Check Programmable Parameters |
| 723-08 | 342-08 | Secondary Engine Speed signal abnormal |
| 729-05 | 617-05 | Inlet Air Heater Current Low/open circuit |
| 729-06 | 617-06 | Inlet Air Heater Current High/grounded |