ADJUSTER A-HYD 8H2689 - Caterpillar

Operation Description: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 of this manual for additional information on the individual switches.The possible causes of these failures are listed below:
Open signal circuit in the harness.
The switch has failed.
The ECM has failed, but is unlikely.Test Step 1. CHECK THE SWITCH
Locate the switch that corresponds to the indicator that is located on the display module. (If necessary, use the Electrical Schematic to assist 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 Expected Result:The alert indicator is no longer active on the main display module.Results:
YES - The alert indicator is no longer active on the main display module.Repair: The switch has failed. Replace the switch. STOP
NO - The alert indicator remains on the main display module. The harness is open or the ECM has failed. ECM failure is unlikely. 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.
Verify that the signal wire is still disconnected.
Measure the pull-up voltage from the signal wire to the ground wire with a calibrated digital multimeter. Expected Result:The voltage is either approximately 5 VDC or 12.5 VDC.Results:
YES - The voltage is either approximately 5 VDC or 12.5 VDC. Proceed to Test Step 4.
NO - The voltage is not correct. Proceed to Test Step 3.Test Step 3. CHECK THE SIGNAL CIRCUIT OF THE HARNESS.
Turn the keyswitch to the OFF position.
Use the Electrical Schematic to trace the signal wire from the switch to the ECM.
Determine the signal contact (connector contact) of the harness at the ECM.
Disconnect the harness connectors J1 and J2 from the ECM.
At the harness connector for the ECM, measure the resistance between the signal contact and contact 2 of the switch. Expected Result:The resistance is less than 5 ohms. Results:
YES - The resistance is less than 5 ohms. The signal circuit of the harness is correct. Proceed to Test Step 4.
NO - The resistance is greater than 5.0 ohms. Repair: The signal circuit of the harness is not correct. Repair or replace the harness.STOPTest Step 4. CHECK THE GROUND CIRCUIT OF THE HARNESS.
Verify that the keyswitch is still in the OFF position.
Verify that harness connectors J1 and J2 remain disconnected.
Use the Electrical Schematic to trace the ground for the switch.
At the switch, measure the resistance between the ground wire and frame ground. Expected Result:The resistance is less than 5 ohms. Results:
YES - The resistance is less than 5 ohms. The ECM may have failed, however, ECM failure is unlikely.Repair: Exit this procedure and perform this procedure again.Ensure that you have the latest version of software for your specific machine and ECM. Refer to the Testing and Adjusting, "Electronic Control Module (ECM) - Flash Program" section of this manual for the correct procedure for flashing.Turn the disconnect switch to