Usage:
Diagnostic Codes
Diagnostic codes are provided to alert the operator that a problem exists and to indicate the nature of the problem to the service technician.
Diagnostic codes consist of two parts. The CID and FMI. The CID, or Component IDentifier, indicates which component in the system the diagnostic code is for. The FMI, or Failure Mode Identifier indicates what the failure mode is. Refer to Diagnostic Terminology in this section for additional details.
Diagnostic codes may be viewed on an Electronic Service Tool (ET or ECAP). To troubleshoot a diagnostic code, refer to the Diagnostic Codes Cross Reference Sheet in this section under the specific code number. The code number will direct you to a procedure in Section 5: Functional Tests.
Active Diagnostic Codes
An active diagnostic code represents a problem with the electronic control system that should be investigated and corrected as soon as possible. Repairing the cause of an ACTIVE diagnostic code will cause it to be cleared from ACTIVE Diagnostics Screen of an Electronic Service Tool.
Logged Diagnostic Codes
When the ECM generates a diagnostic code, it usually logs the code in permanent memory within the ECM. The ECM has an internal diagnostic clock and will record the hour of the first occurrence, the hour of the last occurrence and the number of occurrences of the code.
Knowing when and how often the code was generated can be a valuable indicator when troubleshooting intermittent problems.
An Electronic Service Tool can retrieve and delete Logged codes. Any Logged diagnostic codes will automatically be deleted if no additional occurrences are recorded in 100 hours.
When investigating logged diagnostic codes, keep in mind the following information.
- * Some diagnostic codes may be sensitive, and may log occurrences that did not result in operator or pilot complaints. If the time the code was logged does not correlate to a complaint, there may be nothing to fix.
- * The most likely cause of an intermittent problem is a faulty connection or damaged wiring. Next likely is a component failure (sensor or switch). Least likely is failure of the ECM itself.
- * Diagnostic codes that are logged repeatedly may indicate a problem that needs special investigation.
- * The most likely cause of an intermittent problem is a faulty connection or damaged wiring. Next likely is a component failure (sensor or switch). Least likely is failure of the ECM itself.
To troubleshoot a Logged diagnostic code, refer to the Quick Reference Sheet For Diagnostic Codes in this section. The code number will direct you to a procedure in Section 5: Functional Tests. If the symptoms continue, use the proper procedure for troubleshooting the symptoms that have been experienced by the operator. Refer to Section 3: Troubleshooting Without a Diagnostic Code.
NOTE: Always clear logged diagnostic codes after investigating and correcting the problem which generated the code.
Using ECAP To Display Active Or Logged Diagnostic Codes
2. Turn the Engine Control Switch to the ON position, engine OFF.
3. Select the Display Diagnostics/Events option from the menu.
4. Each diagnostic code CID and FMI are listed on the left and followed by a text description.
5. The ECAP also displays number of times the diagnostic code occurs and the engine hours at the first and last occurrence of the diagnostic code.
- (a) The ACTIVE bar indicates the diagnostic is occurring.
- (b) No text present, as shown on the first two diagnostics, indicates that two codes are logged but are not active.
6. The diagnostic status display is located on the far right of the display window.
Figure 4.15 - Example ECAP Diagnostic Display Screen
Using ET To Display Active Diagnostic Codes
1. Connect ET and the Communication Adapter Tool to the Service Tool connector.
2. Turn the Engine Control Switch to the ON position, engine OFF.
3. Select the Display Active Diagnostics option from the Tools Menu.
4. Each Diagnostic Code CID and FMI are listed on the left followed by a text description
Figure 4.16 - Example ET Active Diagnostic Code Screen
Using ET To Display Logged Diagnostic Codes
1. Connect ET and the Communication Adapter Tool to the Service Tool connector.
2. Turn the Engine Control Switch to the ON position, engine OFF.
3. Select the Display Logged Diagnostics option from the Tools Menu.
4. Each Diagnostic Code CID and FMI are listed on the left followed by a text description.
Figure 4.17 - Example ET Logged Diagnostic Code Screen
Diagnostic Code Terminology
- Component Identifier (CID)
- Two or three digit code which is assigned to each component or system.
- Failure Mode Identifier (FMI)
- Type of failure the component experienced (adopted from SAE standard practice J1587 diagnostics).
Diagnostic And Flash Codes - Indexed By CID-FMI
Flash Codes
Reading Diagnostic Flash Codes
The ECM provides an output that drives a Diagnostic Lamp to indicate the presence of a current (or active) diagnostic condition or an electronic governing/control system problem. The Flash Code associated with an ACTIVE diagnostic condition can be read using the Diagnostic Lamp. In most cases, the diagnostic will also be logged in permanent memory aid in troubleshooting intermittent problems. Logged diagnostics can NOT be read using the Diagnostic Lamp, an electronic service tool (ET or ECAP) is required.
The Diagnostic Lamp will illuminate whenever the ECM is powered up (Engine Control Switch turned ON) for a five second lamp operation self test. The Diagnostic Lamp will then indicate a diagnostic message in a series of Diagnostic Lamp flashes. The first sequence of flashes represents the first digit of a diagnostic Flash Code. After a two second pause, a second sequence of flashes will occur which represent the second digit of the Flash Code. Any additional Flash Codes will follow after a pause and will be displayed in the same manner.
NOTE: It is suggested the Diagnostic Flash Codes be used only to indicate the nature of a diagnostic code occurrence, not to perform detailed troubleshooting. Troubleshooting should be performed using Diagnostic Codes obtained with an electronic service tool.