PROTECTOR GP-SIDE BAR 1222688 - Caterpillar

When a problem exists with a switch, further troubleshooting may be necessary to isolate the problem. Refer to the Systems Operations, "Electrical Input Components" section for additional information on the individual switches.The possible causes of these failures are listed below:
The signal circuit in the machine harness is open.
The switch has failed.
The ECM has failed.Test Step 1. Check For An Open In The Harness
Locate the switch that corresponds to the indicator that is located on the display module. (If necessary, use the Electrical System Schematic to assist in locating the switch.)
Disconnect the signal wire from the switch.
Place a jumper wire from the signal wire to the ground wire. Expected Result:The alert indicator is no longer active on the main display module.Results:
OK - The alert indicator is no longer active on the main display module.Repair: The switch has failed. Check or replace the switch. STOP
NOT OK - The alert indicator remains on the main display module. The machine harness is open or the ECM has failed. Proceed to test step 2.Test Step 2. Check The Voltage Of The ECM
Remove the jumper that was used in the previous test step.
The signal wire remains disconnected.
Measure the pull-up voltage from the signal wire to the ground wire with a digital multimeter. Expected Result:The voltage is 8 1.0 VDC.Results:
OK - The voltage is 8 1.0 VDC.Repair: The voltage is correct. The ECM has failed.