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| Illustration 1 | g01294832 |
Connections for the hydraulic oil level switch | |
Use this procedure in order to troubleshoot the hydraulic oil level switch under the conditions that are listed below:
- The hydraulic oil is at a normal level and the IQAN-MDM is warning the operator of a "LOW" hydraulic oil condition.
- The hydraulic oil is below the lower limit and the IQAN-MDM is NOT warning the operator of the "LOW" hydraulic oil condition.
The possible causes of this failure are listed below:
- The signal circuit in the machine harness is open.
- The signal circuit is shorted to ground.
- The ground circuit is open.
- The switch has failed.
- The module has failed.
Test Step 1. VERIFY THE STATUS OF THE LEVEL SWITCH.
- Turn the disconnect switch and the key start switch to the ON position.
- Verify that the level switch does not report a low level, even though the level is low.
Expected Result:
The level switch does not report a low level, even though the level is low.
Results:
- OK - The level switch does not report a low level, even though the level is low. Proceed to test step 2.
- NOT OK - The level switch reports a low level even when the level is normal. Proceed to test step 5.
Test Step 2. CHECK THE SWITCH
- The disconnect switch and the key start switch remain in the ON position.
- Disconnect the hydraulic oil level switch from the machine harness.
Expected Result:
The status of the hydraulic oil level changes from "OK" to "LOW".
Results:
- OK - The status of the hydraulic oil level changes from "OK" to "LOW". The switch has failed.
Repair: Replace the Switch.
STOP
- NOT OK - The status of the hydraulic oil level did not change. Proceed to test step 3.
Test Step 3. CHECK THE IQAN-XT2 MODULE
- Turn the disconnect switch and the key start switch to the ON position.
- At the machine harness connector for the switch, measure the voltage between contact 2 (wire 496-WH) and contact 1 (wire A982-OR) of the machine harness.
Expected Result:
The voltage is 5.0 ± 0.5 DCV.
Results:
- OK - The voltage is 5.0 ± 0.5 DCV. The voltage is correct. The module has failed.
Repair: It is unlikely that the module has failed. Exit this procedure and perform this procedure again. If the cause of the failure is still unknown, replace the module.
STOP
- NOT OK - The voltage is not 5.0 ± 0.5 DCV. The voltage is not correct. Proceed to test step 4.
Test Step 4. CHECK THE SIGNAL CIRCUIT IN THE MACHINE HARNESS
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the machine harness connector from the IQAN-XT2 module.
- At the machine harness connector for the switch, measure the resistance between contact 2 (wire 496-WH) of the machine harness connector and frame ground.
Expected Result:
The resistance is greater than 5000 ohms.
Results:
- OK - The resistance is greater than 5000 ohms. The circuit is correct. The IQAN-XT2 module has failed.
Repair: It is unlikely that the module has failed. Exit this procedure and perform this procedure again. If the cause of the failure is still unknown, replace the module.
STOP
- NOT OK - The resistance is less 5000 ohms. The Circuit is not correct. The harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 5. CHECK THE SWITCH
- The disconnect switch and the key start switch remain in the ON position.
- Verify that the status of the hydraulic oil level switch is "LOW".
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the hydraulic oil level switch from the machine harness.
- Place a jumper wire between contact 2 (wire 496-WH) and contact 1 (wire A982-OR).
- Turn the disconnect switch and the key start switch to the ON position.
- Verify the status of the hydraulic oil level switch.
Expected Result:
The status of the hydraulic oil level changed from "LOW" to "OK".
Results:
- OK - The status of the hydraulic oil level changed from "LOW" to "OK". The switch has failed.
Repair: Replace the switch.
STOP
- NOT OK - The status of the hydraulic oil level did not change. Proceed to test step 6.
Test Step 6. CHECK THE SIGNAL CIRCUIT
- Turn the key start switch and the disconnect switch to the OFF position.
- Remove the jumper wire from contact 1 (wire A982-OR) of the machine.
- Short the unattached end of the jumper wire to frame ground.
- Turn the disconnect switch and the key start switch to the ON position.
- Verify the status of the hydraulic oil level switch.
Expected Result:
The status of the hydraulic oil level changed from "LOW" to "OK".
Results:
- OK - The status of the hydraulic oil level changed from "LOW" to "OK". The ground circuit of the machine harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
- NOT OK - The status of the hydraulic oil level did not change. Proceed to test step 7.
Test Step 7. CHECK THE SIGNAL CIRCUIT
- Turn the key start switch and the disconnect switch to the OFF position.
- Remove the jumper wire from the machine harness connector of the switch.
- Disconnect the machine harness connector from the IQAN-XT2 module.
- Measure the resistance of the signal circuit from contact IQAN XT2 A0 - 35 (wire 496-WH) to contact 2 (wire 496-WH) of the machine harness connector for the switch.
Expected Result:
The resistance is less than 5 ohms.
Results:
- OK - The resistance is less than 5 ohms. The circuit is correct. The IQAN-XT2 module has failed.
Repair: It is unlikely that the module has failed. Exit this procedure and perform this procedure again. If the cause of the failure is still unknown, replace the module.
STOP
- NOT OK - The resistance is greater than 5000 ohms. The signal circuit is open. The machine harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP