AccuGrade GPS / Single UTS / Site and Laser Reference v11 for Excavators Electrical Power Supply (Angle Sensor) Caterpillar

System Operation Description:

The angle sensor is not receiving power.

The probable conditions that cause this symptom are in the following list:

• Display is not turned "ON".

• A fuse is open or a circuit breaker is open.

• Failed AccuGrade Radio

• Power Jumper

• Power Module

• Damaged harness or connector

Test Step 1. VERIFY THAT THE DISPLAY WILL TURN ON.

1. Ensure that the battery disconnect switch and the key start switch are in the ON position.

2. Turn the display ON.

Expected Result:

The display turns ON.

Results:

• OK - The display turns ON. Proceed to Test Step 2.

• NOT OK - The display does not turn ON.

  Repair: Refer to the Troubleshooting section of Service Manual, KENR8980, "Electrical Power Supply (Display)".

  STOP

Test Step 2. VERIFY THAT THE ANGLE SENSOR POWERS UP.

1. Press the "Menu" button on the display until the "Setup Menu" soft key is displayed on the far left of the display screen.

2. Use the up arrow button or the down arrow button in order to select the "Diagnostic" option. Then press the "OK" button.

3. Verify that all of the sensors that are listed on the "Diagnostic" screen are "Connected".

Expected Result:

All of the sensors that are listed are "Connected".

Results:

• OK - All of the sensors that are listed are "Connected".

  Repair: The cause of the problem was Display. The Display was turned Off. Return the machine to service.

  STOP

• NOT OK - All of the sensors that are listed are not "Connected". Proceed to Test Step 3.

Test Step 3. CHECK THE POWER TO THE ANGLE SENSORS.

1. Disconnect the harness connectors from the connectors for the angle sensor.

2. Measure the voltage between pin A and pin F on the harness connector for the sensor.

Expected Result:

The measured voltage is approximately machine voltage.

Results:

• OK - The measured voltage is approximately machine voltage.

  Repair: The sensor has failed. Replace the failed sensor.

  STOP

• NOT OK - The voltage is not approximately machine voltage. Proceed to Test Step 4.

Test Step 4. CHECK FUSE OR CIRCUIT BREAKER.

1. Check the fuse or the circuit breaker.

   Note: Use the schematic for your machine in order to identify the correct fuse or the circuit breaker.

Expected Result:

The fuse or the circuit breaker is "OK".

Results:

• OK - The fuse or the circuit breaker is "OK". Proceed to Test Step 5.

• NOT OK - The fuse or the circuit breaker has failed.

  Repair: Replace the fuse or the circuit breaker.

  STOP

Test Step 5. CHECK FOR AN OPEN POWER JUMPER IN THE POWER CIRCUIT IN THE HARNESS.

1. Use the AccuGrade electrical schematic for the machine in order to determine if a power jumper is used.

2. Disconnect the power jumper.

3. Place a jumper between pin B and pin C at the harness connector of the Display.

4. Turn the Display ON.

Expected Result:

The AccuGrade radio powers up.

Results:

• OK - The power jumper has failed.

  Repair: Replace the power jumper.

  STOP

• NOT OK - The sensors that are listed in the "Diagnostic" screen are not "Connected". The power jumper is not the cause of the failure. Proceed to Test Step 6.

Test Step 6. CHECK FOR A SHORTED POWER CIRCUIT IN THE HARNESS.

1. Check the harness for the Display for a short circuit condition.

   Note: Use the schematic for your machine in order to identify the wiring for the power circuit.

Expected Result:

A short circuit condition is not present in the harness.

Results:

• OK - A short circuit condition is not present in the harness. Proceed to Test Step 7.

• NOT OK - A short circuit condition is present in the harness.

  Repair: Repair the harness or replace the harness.

  STOP

Test Step 7. CHECK FOR AN OPEN POWER CIRCUIT IN THE HARNESS.

1. Check the harness for the Display for an open circuit condition.

   Note: Use the schematic for your machine in order to identify the wiring for the power circuit.

Expected Result:

An open circuit condition is not present in the harness.

Results:

• OK - An open circuit condition is not present in the harness. The power module (if equipped) has failed.

  Repair: Replace the power module.

  STOP

• NOT OK - An open circuit condition is present in the harness.

  Repair: Repair the harness or replace the harness.

  STOP