MODULE GP-KEYPAD 4788977 - Caterpillar

The data is erratic, intermittent, or incorrect. The signal from the active control head is abnormal or out of range.Troubleshooting:If this error code is with an integrated control head (ICH) as the active station, replace the ICH. If this error code is active with a slim line control head or the side mount control head as the active station, continue with this procedure.Test Step 1. ACTIVATE THE STATION AND DUPLICATE THE PROBLEM.
Turn the keyswitch ON.
Activate the suspect station.
Ensure that the diagnostic code is active. Expected Result:The diagnostic code is active.Results:
OK - The diagnostic code is active. Go to Test Step 2.
NOT OK - The diagnostic code is NOT active.STOPTest Step 2. CHECK ELECTRICAL CONNECTORS AND WIRING.
Turn the keyswitch OFF.
Inspect the wiring from the control station processor to the slim line control head or the side mount control head for the following conditions:
Abrasion
Corrosion
Incorrect attachment
Pinch points
Ensure that the following items are correctly mated and are in good condition: connectors, pins and sockets. Expected Result:All of the following are properly mated and in good condition: connectors, pins, and wires.Results:
OK - All connectors, pins, and wires are properly mated and in good condition. Go to Test Step 3.
NOT OK - All connectors, pins, and wires are NOT properly mated and in good condition.Repair: Repair the parts or replace the parts.After the repair, verify that the diagnostic is NOT active.STOPTest Step 3. CHECK THE OPERATION OF THE SLIM LINE CONTROL HEAD OR THE SIDE MOUNT CONTROL HEAD.
Illustration 1 g01029957
Disconnect the cable between the control station processor and the slim line control head or the side mount control head. Refer to Illustration 1.
Insert a 12-pin breakout "T" between the control station processor and the processor for the slim line control head or the side mount control head. Refer to Illustration 1.
Table 1
Measure from Pin Measure to Pin Number Minimum Maximum
1 (+Vref) 3 (return) 4.75 VDC 5.25 VDC(1)
2 (throttle) 3 (return) 0.6 VDC 5.0 VDC(2)
(1) The nominal voltage is 5.00 VDC
(2) The minimum voltage and the maximum voltage will vary. This depends on where the throttle dead bands are set. The voltages should be the same for forward throttle and reverse throttle.
Use a digital volt meter (DVM) in order to verify the operation of the slim line control head or the side mount control head. Refer to Table 1. Expected Result:The voltages are within the limits that are listed in table 1.Results:
OK - The voltages are within the limits that are listed in the table.Repair: Replace the control station processor.After the repair, recheck the operation of the control head in order to ensure that the diagnostic code is NOT active.STOP
NOT OK - The voltages are NOT within the limits that are listed in the table.Repair: Replace the slim line control head or the side mount control head.After the repair, recheck the operation of the control head in order to ensure that the diagnostic code is NOT active.STOP