AccuGrade Laser System Caterpillar

Refer to the electrical schematic for a full system schematic.

This diagnostic code is associated with the calibration of the lift valve and the tilt valve. Sensor Data from the laser receivers is not being detected by the display during the valve calibration.

System Response:

When this diagnostic code is active, the valve calibration procedure cannot be completed.

Test Step 1. CHECK THE LASER RECEIVER ICONS

1. Verify that the laser receiver icons are shown on the display as connected icons.

Expected Result:

The laser receiver icons are shown on the display as connected icons.

Refer to Systems Operation, Troubleshooting, & Testing and Adjusting, "Modes of Operation" for more information about the laser receiver icons.

Results:

• YES - The laser receiver icons are shown on the display as connected icons. Proceed to Test Step 3.

• NO - The laser receiver icons are not shown on the display as connected icons. Proceed to Test Step 2.

Test Step 2. CHECK THE POWER LED ON THE LASER RECEIVERS

1. Verify that the power LED on the laser receivers is illuminated.

Results:

• YES - The power LED on the laser receivers is illuminated. Proceed to Test Step 3.

• NO - The power LED on the laser receivers is not illuminated. Proceed to Test Step 5.

Test Step 3. CHECK THE LASER TRANSMITTER

1. Verify that the laser transmitter is working properly.

Expected Result:

The laser transmitter is working properly.

Results:

• YES - the laser transmitter is working properly. Proceed to Test Step 4.

• NO - the laser transmitter is not working properly.

  Repair: Contact your Dealership's Technical Communicator for a possible consultation with Caterpillar.

  Stop.

Test Step 4. CHECK THE LASER BEAM

Illustration 1	g01098953
(1) Laser Beam (2) laser Receivers

1. Verify that the laser beam is striking the laser receivers.

Expected Result:

The laser beam is striking the laser receivers.

Results:

• YES - The laser beam is striking the laser receivers. Proceed to Test Step 6.

• NO - The laser beam is not striking the laser receivers.

  Repair: Adjust the transmitter in order to ensure that the laser beam is striking the laser receivers. Perform the valve calibration again.

  Stop.

Test Step 5. CHECK THE MACHINE VOLTAGE

1. Disconnect the wire harness from the laser receiver.

2. Measure the voltage between pin "A" and pin "F".

Expected Result:

The voltage is machine voltage.

Results:

• YES - The voltage is machine voltage.

  Repair: Repair or replace the laser receiver. Repeat the calibration procedure.

  Stop.

• NO - The voltage is not machine voltage. Proceed Test Step 7

Test Step 6. CHECK THE CAN TERMINATION RESISTORS.

1. Place the key start switch and the disconnect switch in in the OFF position.

2. Disconnect the 3-pin connector from both of the termination resistors.

3. Measure the resistance across contact A (wire L854-YL) and contact B (wire L855-GN) for both resistors. Note the resistance.

Expected Result:

The resistances measured are 120 ± 12 ohms.

Results:

• YES - The resistances measured are 120 ± 12 ohms. Reconnect the resistors. Proceed to Test Step 7

• NO - One or both resistances measured is NOT 120 ± 12 ohms.

  Repair: Replace the termination resistor(s) that did not measure 120 ± 12 ohms.

  Stop.

Test Step 7. CHECK THE WIRING HARNESS OF THE LASER RECEIVER

1. Disconnect the wiring harness from the laser receiver.

2. Use the multimeter probes in order to measure the resistance from each contact in one end of the harness to the same contact in the opposite end of the harness.

Expected Result:

The resistance is greater than 5 ohms.

Results:

• OK - The resistance is greater than 5 ohms. There is an open in the machine harness.

  Repair: Repair the harness or replace the harness.

  Stop.

• NOT OK - The resistance is less than 5 ohms. The harness circuit is correct. Reconnect the wire harnesses and repeat the calibration procedure. If the diagnostic code is not active at this time, the initial diagnostic code may have been caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. If the diagnostic code continues to occur, contact your dealership's Technical Communicator for a possible consultation with Caterpillar. Stop.