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| Illustration 1 | g01548493 |
The left laser receiver was not detected with the display in single elevation mode.
System Response:
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| Illustration 2 | g01105865 |
The device status icon for the left laser receiver will not be shown on the display. Refer to Illustration 2.
Test Step 1. CHECK THE POWER LED
Ensure that the power to the display is on.
- Check that the left laser receiver has powered up by verifying that the power LED is illuminated.
Expected Result:
Power LED on the left laser receiver is illuminated.
Results:
- YES - The LED on the left laser receiver is illuminated. Proceed to Test Step 5.
- NO - The LED on the left laser receiver is not illuminated. Proceed to Test Step 2.
Test Step 2. CHECK THE MACHINE VOLTAGE
- Disconnect the wire harness from the laser receiver.
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Once the system is placed in automatic mode, blade movement may occur. Ensure that all personnel are clear of the blade before you place the system in automatic mode. Personal injury or death from crushing could occur. |
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- Measure the voltage between pin "A" and pin "F".
Expected Result:
The voltage is machine voltage.
Results:
- YES - The voltage that is measured is machine voltage. Proceed to Test Step 5.
- NO - The voltage that is measured is not machine voltage. Proceed to Test Step 4.
Test Step 3. CHECK FOR VOLTAGE
- Disconnect the cable at the knuckle connectors.
- Check for machine voltage between "pin A" and "pin F" at the harness connector box. The harness connector box is located on the knuckle connectors.
Expected Result:
The voltage is machine voltage.
Results:
- YES - The voltage is machine voltage. Proceed to Test Step 5.
- NO - The voltage is not machine voltage. Proceed to Test Step 4.
Test Step 4. CHECK THE POWER SUPPLY MODULE
Refer to the Electrical Schematic for the machine.
- Access the power module. Remove the 8 pin connector that is opposite of the symbol for the battery from the main harness.
- Install a jumper wire between pin "E", pin "F" and frame ground (GND) on the connector that is located on the power supply.
- Measure the voltage between pin "G" and pin "H" on the connector that is located on the power module .
Expected Result:
The voltage that was measured between pin "G" and pin "H" on the connector for the power module is machine battery voltage.
Results:
- YES - The voltage that is measured between pin "G" and pin "H" on the connector for the power module is machine battery voltage.
Repair: There is a problem with the coiled harness that connects from the knuckle connectors to the electric mast or the coiled harness that connects from the laser receiver to the base of the electric mast. Check each harness for an open condition. Repair the wire harness or replace the wire harness.
STOP
- NO - The voltage that is measured between pin "G" and "H" on the connector of the power module is not machine voltage.
Repair: Repeat this Test Step before replacing the power supply. Replace the power supply.
STOP
Test Step 5. INSPECT THE HARNESS.
- Move the "Power/Setup" Switch on the display to the "OFF" position.
- Turn the key start switch and the disconnect switch to the "OFF" position.
- Disconnect the harness connectors for the right or the left electric mast. Disconnect the harness connectors for the laser receivers.
- Carefully inspect each harness for signs of abrasion, nicks, or cuts.
The following areas are locations that should be checked:
- Exposed insulation
- Points of rubbing wire
- Exposed insulation
- Check the connectors for moisture or corrosion.
Note: If corrosion is evident on the contacts or the connector, use only denatured alcohol to remove the corrosion. Use a cotton swab or a soft brush to remove the corrosion. Do not use cleaners that contain trichloro-ethylene because trichloro-ethylene may damage the connector.
Expected Result:
The AccuGrade - Grade Control System harnesses should be free of corrosion, moisture and abrasion.
Results:
- OK - The AccuGrade - Grade Control System harnesses are free of corrosion, moisture, and abrasion. Proceed to Test Step 6.
- NOT OK - A problem exists with the connector, the wiring or the wiring harness.
Repair: Repair the affected AccuGrade - Grade Control System harness or replace the affected AccuGrade - Grade Control System harness.
Proceed to Test Step 6.
Test Step 6. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Reconnect the AccuGrade - Grade Control System harnesses to the left electric mast.
- Reconnect the AccuGrade - Grade Control System harnesses to the left laser receiver.
- Turn the key start switch and the disconnect switch to the "ON" position.
- Move the "Power/Setup" Switch on the display to the "ON" position.
Expected Result:
The diagnostic code is no longer active.
Results:
- OK - The diagnostic code is no longer active. The initial diagnostic code was probably caused by a poor electrical connection and/or a short at one of the harness connectors that was disconnected and then reconnected. Resume normal machine operation.STOP
- NOT OK - The diagnostic code is still active. Proceed to Test Step 7.
Test Step 7. CHECK THE TERMINATION RESISTOR.
- Turn the "Power/Setup" Switch on the AccuGrade - Grade Control System display to the "OFF" position.
- Turn the key start switch and the disconnect switch for the machine to the "OFF" position.
- Disconnect the 3-pin connector from all of the termination resistors.
- Measure the resistance between contact A (wire L854-YL) and contact B (wire L855-GN) for all four resistors. Note the resistance.
Expected Result:
The resistance measurements are 120 ± 12 ohms.
Results:
- YES - The resistance measurements are 120 ± 12 ohms. Reconnect the resistors.
Repair: If the diagnostic code "CB 36" is still active, contact your Caterpillar dealership.
STOP
- NO - One or both resistance measurements are NOT 120 ± 12 ohms.
Repair: Replace the termination resistor(s) that did not measure 120 ± 12 ohms.
STOP