PUMP GP-MAIN HYDRAULIC 4992268 - Caterpillar

Illustration 1 g00481278
Schematic For Alarm Module (ALM)The alarm module (ALM) is available as an option. The ALM can be mounted on the instrument panel. The ALM can also be mounted at a distance as a remote annunciator. The ALM is used to satisfy requirements from customers and The National Fire Protection Association (NFPA) by annunciating the presence of a fault.The ALM communicates with the GSC by a serial data link. When the data link malfunctions, all of the indicators on the ALM that are controlled by the data link, flash at a rate of .5 Hz.Note: The maximum number of modules that can be connected to the serial data link is three. The maximum distance between a module and the GSC is 305 m (1000 ft). If these specifications are not met, there is a possibility for the ALM indicators to flash. Also, there is a possibility for the GSC to declare a diagnostic code of a CID 333. If the modules are not in compliance with the specifications, reduce the number of modules and/or shorten the distance to modules. Note: Faults are created when the harness connector (40 contact) is disconnected from the GSC during these troubleshooting procedures. Clear these created faults after the particular fault is corrected. In a properly operating system, when the harness connector is removed from the GSC, the following diagnostic codes are recorded.
CID 100 FMI 2 pressure sensor (engine oil)
CID 110 FMI 2 temperature sensor (engine coolant)
CID 111 FMI 3 fluid level sensor (engine coolant)
CID 190 FMI 3 speed sensor (engine)
CID 331 FMI 2 switch (engine control)
CID 336 FMI 2 switch (engine control)The following condition is a possible cause of a CID 333 FMI 4.
A short to the "B-" of the signal for the data is present.The GSC treats this diagnostic code as an alarm fault. Clear the diagnostic code from the fault log after troubleshooting is complete.Note: If a CID 333 FMI 4 is showing on the upper display and no alarm module is installed, check for a short. Check between the auxiliary terminal strip and the GSC.
Check the fault status (Active/Inactive).
Turn the ECS to OFF/RESET and then turn the ECS to STOP.
Press the alarm codes key.
Verify that a CID 333 FMI 4 is showing.
If the diagnostic code is not showing, enter the service mode and view the fault log (OP1). Verify that the diagnostic codes are showing. Expected Result: A CID 333 FMI 4 is showing as active or inactive. Results:
No - A CID 333 FMI 4 has not occurred (is NOT active and is NOT inactive). STOP.
Yes - A CID 333 FMI 4 is active. Proceed to 2.
Yes - A CID 333 FMI 4 is inactive. Proceed to 4.
Check the voltage of the signal for the data.
Turn the ECS to STOP.
At the ALM, measure the DC voltage from terminal 2 (positive meter lead) to terminal 7 (negative meter lead). Expected Result: The voltage that is measured should change constantly. The voltage should change within the range of 0 to 10