Diagnostic codes are used by the electronic system to alert the operator that a problem exists. A diagnostic code also indicates the nature of the problem to the service technician.
Diagnostic Codes may be viewed by using the Caterpillar Electronic Technician (Cat ET). The Component Identifier (CID) identifies a specific component in the system that is described by the diagnostic code. The Failure Mode Identifier (FMI) indicates the failure mode.
The code number will direct you to a procedure in Troubleshooting, "Troubleshooting With A Diagnostic Code". Do not confuse diagnostic codes with diagnostic events. Refer to the Troubleshooting, "Event Codes" section of this manual for further information on event codes.
An active diagnostic code represents a problem with the electronic control system. Correct the condition as soon as possible. If the condition that generates the diagnostic code occurs only for a brief moment, the message will disappear and the diagnostic code will be logged in the memory of the Electronic Control Module (ECM).
When the ECM generates a diagnostic code, the ECM will log the code in the permanent memory of the ECM. The ECM has a diagnostic clock that is internal. This clock records the hour of the first occurrence, the hour of the last occurrence, and the number of occurrences of the code. Knowing the timing of the code and knowing the frequency of the code can be a valuable indicator. These indicators are helpful when problems that are intermittent are being investigated.
Note: Cat ET can be used to retrieve logged codes and Cat ET can be used to erase logged codes. Logged diagnostic codes will automatically be deleted if no additional occurrences are recorded in 100 hours. Be aware of the following information when logged diagnostic codes are investigated.
- Some diagnostic codes may log occurrences that did not result in operator complaints. A diagnostic code is logged at a specific time. This time should correlate to a complaint. A repair may not be necessary if there is no correlation.
- The most likely cause of an intermittent problem is a faulty connection or damaged wiring. The next most likely cause of an intermittent failure is a component failure such as a sensor or a switch. The least likely cause of an intermittent problem is a failure of the ECM.
- Diagnostic codes that are logged repeatedly may indicate a problem that needs special investigation.
- The code number will direct you to a procedure in troubleshooting guide. If the symptoms continue, use the proper procedure for troubleshooting the symptoms that have been experienced by the operator. Refer to Troubleshooting Without A Diagnostic Code.
Note: Always clear logged diagnostic codes after investigating and correcting the problem which generated the code.
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| Illustration 1 | g01040769 |
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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 output signal for the sensor is below 0.2 VDC or above 4.8 VDC.
Cross-Reference for SPN-FMI Code to CID-FMI (Diagnostics)
Portions of this material are reprinted with permission from SAE J1939DA_201607© 2016 SAE International. SAE International is not responsible for any use or translation of this material, in whole or in part. Please contact SAE International to obtain a complete copy of SAE J1939DA_201607, the official definitive source of this standard.
| Cross-Reference for SPN-FMI Code to CID-FMI (Diagnostics) | ||
|---|---|---|
| SPN/FMI Code | CID-FMI or EID | Description of Code |
| 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 |
| 108-03 | 274-03 | Atmospheric Temperature Sensor open/short to +batt |
| 108-04 | 274-04 | Atmospheric Temperature 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 |
| 102-03 | 273-03 | Turbo Outlet Pressure open/short to +bat |
| 102-04 | 273-04 | Turbo Outlet Pressure short to ground |
| 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 |
| 190-02 | 190-02 | Loss of Engine Speed Signal |
| 190-11 | 190-011 | Engine Speed Sensor mechanical failure |
| 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 |
| 637-13 | 261-13 | Engine Timing calibration required |
| 234-02 | 253-02 | Personality Module mismatch |
| 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 |
| N/A | 1929-03 | Fuel Return Temperature Sensor voltage high/short to +bat |
| N/A | 1929-04 | Fuel Return Temperature Sensor voltage low/short to ground |
| 723-02 | 342-02 | Loss of Secondary Engine Speed signal |
| 723-11 | 342-11 | Secondary Engine Speed Sensor mechanical failure |
| 630-02 | 268-02 | Check Programmable Parameters |