PLATE-CENTER 6Y4833 - Caterpillar

Electronic Monitoring System Troubleshooting
Begin your troubleshooting by gathering reliable information. Perform these four tests and write down your results. Compare the results of each of the steps with the expected results. If the actual results differ from the expected results, proceed to the probable cause to begin the diagnostic procedure.The EMS can be checked for correct operation with four basic test procedures. The test procedures must be followed in order. Start with Test 1. The results from Test 2 depend on the results from Test 1, etc.There are many types of starting systems in the different vehicles with EMS. In the tests that follow, you will be instructed to place the key start switch in the ON position. Vehicles with the key type start switch have an OFF, ON, and START position. There are many vehicles with EMS that have a start switch with an OFF, HEAT, and START position. This second type of start switch will not have an ON position. The disconnect switch and the key start switch have the same ON position. The disconnect switch and the key start switch have the same OFF position for the second type of starting system.The disconnect switch and the parking brake must be in the ON position during all these tests.Test 1
Key Start Switch ON
Test Switch ON
Engine OFFExpected Results
All indicators flash.
The action lamp flashes.
The action alarm must be OFF.If the results do not match the expected results, refer to Diagnostic System Procedures. Find the procedure for correcting the unexpected result.Test 2
Key Start Switch ON
Test Switch OFF
Engine OFFExpected Results
The action lamp must flash.
The action alarm must be OFF.
Indicators on the operator monitor panel must match the positions in Table 1.
Table 1
Position Indicator Condition of Indicator
1 Coolant Temperature OFF
2 Coolant Flow FLASH
Brake Oil Pressure OFF
3 Engine Oil Pressure FLASH
4 Brake Air Pressure OFF or FLASH
Brake Oil Pressure OFF
5 Hydraulic Oil Temperature OFF
6 Torque Converter Oil Temperature OFF
Power Train Oil Temperature OFF
Transmission Oil Temperature OFF
7 Parking Brake ON FLASH
Power Train Oil Filter Bypass OFF
Accumulator Pressure FLASH or OFF
8 Alternator FLASH
9 Fuel Level FLASH or OFF
10 Power Train Oil Filter Bypass OFF
Steering FLASH
Transmission Filter OFF The low fuel level indicator must flash if the fuel level is 10% of capacity or less.Note: This circuit has a 10 second delay.The Parking Brake ON indicator must flash when the parking brake is engaged.The brake air pressure indicator must flash if the machine has been sitting and the air in the reservoir has drained off.If the indicators match Table 1, check the harnesses and the switches, except for the indicators that are OFF or flashing.
Check the wiring.
If you cannot find the problem in the wiring, drain the fuel tank to check the low fuel level switch.
Remove the control wire from the fuel level switch to check the wiring. After approximately 12 seconds of the control wire being removed, the indicator must flash.
Put the control wire to vehicle ground. The indicator must turn OFF.Note: Know the amount of fuel in the fuel tank.Activate the brakes repetitively