- Display output modules
- Action alarm output
- The following Sensor inputs are included: voltage, frequency, PWM and resistive
- Harness code (validity)
Note: The main display module does not detect switch input faults.
Diagnostic information may be obtained in Service Mode under the following conditions:
- Caterpillar Monitoring System must be in Normal Mode.
- "SERV CODE" must be seen in the display area.
Service Mode allows service personnel to see diagnostic codes. Service Mode also allows personnel to troubleshoot the diagnostic codes that are detected by the main display module. All detected diagnostic codes are shown in the display area. While the main display module is in Service Mode, diagnostic codes can be placed "on-hold" and diagnostic codes can be cleared.
If "- 3 -" appears on the display and the SERVICE MODE Switch is released, the main display module will enter the Service Mode. The main display module leaves Service Mode when the "SERVICE MODE" switch is pressed again. For more information on changing Modes, see Systems Operation, "Modes Of Operation".
Note: When the Caterpillar Monitoring System is placed in Service Mode, diagnostic codes from other engine systems are shown in the display area. In order for these diagnostic codes to be displayed, the other engines must be electronically controlled. The CAT data link allows the transfer of diagnostic information from other electronic control modules to the main display module. This diagnostic information is then shown when the main display module is in Service Mode. Faults from other electronic control modules have a unique MID. This Module Identifier (MID) can be displayed. See the following description of the Module Identifier (MID).
When the Caterpillar Monitoring System is placed in Service Mode, the diagnostics of the Caterpillar Monitoring System are available to assist with troubleshooting of detected faults. Four identifiers are used to specify each detected fault. These identifiers are shown in the Display Area. While a fault is on "HOLD", the Display Area toggles between these identifiers: MID (first display) and CID FMI (second display). These identifiers are listed below.
Module Identifier (MID) - The MID is a three digit code that is shown on the display area. Before the CID FMI replaces the MID in the Display Area, The MID is displayed for approximately one second. This MID shows the electronic control module (ECM) that has diagnosed the fault. Two examples are the monitoring system and the engine control. The MID for the Caterpillar Monitoring System is 030. Some of the Module Identifiers for the primary engine control module are 033, 034, or 036.
Component Identifier (CID) - The Component Identifier identifies faulty components or faulty systems. The CID identifies components such as the following components: engine oil temperature, speed sensor and engine boost pressure. The CID is a four digit code that is shown on the six digit display area. After the MID, the CID and the FMI are displayed together. For a list of diagnostic codes for the main display module, see the Detected Diagnostics table in Testing And Adjusting, "Detected Diagnostics".
Failure Mode Identifier (FMI) - The FMI tells the type of failure that has occurred. The following faults may be identified: voltage above normal, current below normal and abnormal frequency. The FMI is a two digit code that is shown on the display area. After the MID, the CID and the FMI are displayed together. A decimal point precedes the FMI. For a list of the diagnostic codes for the main display module, see Testing And Adjusting, "Detected Diagnostics".
After entering the Service Mode, the MID, the CID, and the diagnostic codes for the first available fault are shown on the Display Area. At this time, the fault that is shown is on "HOLD". When a diagnostic code is on "HOLD", the display continuously toggles between the MID, the CID, and the FMI. While the "Service" inputs and the "Clear" inputs remain open, the display will continue to toggle. Troubleshooting is performed while the fault is on "HOLD".
The "SERV CODE" indicator signifies if the diagnostic code is active or the diagnostic code is logged. If the "SERV CODE" indicator is OFF, the diagnostic code is logged. When a diagnostic code goes from "logged" to "active" during Mode 3 (Service Mode), the Alarm will sound. The Alarm will help the service personnel diagnose the intermittent problems.
Use the "SCROLL" switch to advance to the next recorded diagnostic code. Advancing the display will sequentially show all the recorded Diagnostic Codes in the display area.
When a diagnostic code is corrected, the Service Personnel must clear the diagnostic code from the Main Display Module's memory. A logged diagnostic code can be cleared from the memory of the Main Display Module. This is done by pushing the "CLEAR/MODE" switch upward while the code is on the display area.
Note: When no diagnostic codes have been detected, the Display Area will display the following reading.
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| Illustration 1 | g00533498 |
Note: Faults that have been detected by various other electronic control modules can be cleared by using the main display module. Electronic control modules with an MID of 30 cannot be cleared by using the main display module.
Diagnostic Example
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| Illustration 2 | g00427558 |
Diagnostic Example (1) First display (2) Second display (3) Module identifier (4) Fault present indicator (SERV CODE) (5) Component identifier (CID) (6) Failure mode identifier (FMI) | |
The diagnostic example that was given in the previous illustration is explained in the following paragraphs.
Brief Explanation
The main display module is currently receiving an out-of-range signal from the Engine Coolant Temperature Sensor.
Detailed Explanation
MID (3) is "030". Module identifier "030" means that the fault concerns the Caterpillar Monitoring System.
CID (5) is "0110". Component identifier "0110" means that the fault is in the engine coolant temperature circuit of MID "030". For a list of diagnostic codes for the Caterpillar Monitoring System, see the Detected Diagnostics Table in the Testing And Adjusting, "Detected Diagnostics" section.
The "SERV CODE" indicator (4) means that CID 0110 fault is now present. The Action Alarm will sound when the following conditions are met:
- CID 0110 fault present indicator changes from "ON" to "OFF".
- the Display Area is in the Service Mode.