ROTATING GP-PUMP 2807988 - Caterpillar

Which Generate This Code:This diagnostic code is associated with the Heading Sensor. This diagnostic code is active if the sensor is not detected on the data link.The Heading Sensor is an after-market sensor that connects to machines equipped with a Global Positioning System. The sensor communicates with the Machine ECM via the CAN Data Link.This diagnostic code is caused by abnormal communications between the Machine ECM and the global positioning system through the CAN Data Link. The update rate is not correct. A possible cause of this diagnostic code is listed below:
The Machine ECM is operating intermittently.The CAN Data Link is an input and output of all electronic control modules. The data link is designed to carry communications between the electronic control modules. The data link is not a visible component. The data link consists of internal control circuits and the connecting harness wiring.System Response:If the Heading sensor is working incorrectly, the Cat Grade Control system is unable to determine the heading of the machine. The heading value is used to calculate the correct elevations when excavating a design with slope in one or both directions, mainfall, and cross-slope.Test Step 1. CHECK THE MACHINE HARNESS
Verify that the contacts of the two connectors on the machine harness are properly wired. Refer to Electrical Schematic KENR7987.Expected Result:The harness is wired correctly.Results:
YES - The machine harness is wired correctly. Proceed to Test Step 2.
NO - The machine harness is NOT wired correctly.Repair: Repair or replace the harness.STOPTest Step 2. CHECK THE RESISTANCE OF THE CAN DATA LINK
Place the key start switch and the disconnect switch in the OFF position.
Take the following measurement at the harness connector for the sensor. Measure the resistance across contact "3" and contact "4". Note the resistance.Expected Result:The resistance measurement is 60 ( 5) ohms.Results:
YES - The resistance measurement is 60 ( 5) ohms. Proceed to Test Step 4.
NO - The resistance measurement is NOT 60 ( 5) ohms. Proceed to Test Step 3.Test Step 3. CHECK THE TERMINATION RESISTOR
Disconnect the connector for the termination resistor.
Measure the resistance across contact "A" and contact "B" of the termination resistor. Note the resistance.
Measure the resistance across contact "C" and contact "D" of the quick disconnect at the laser receiver. Note the resistance.Expected Result:The resistance measurement is 60 ( 5) ohms.Results:
YES - The resistance measurement is 60 ( 5) ohms. Proceed to Test Step 4.
NO - The resistance measurement is NOT 60 ( 5) ohms.Repair: If the termination resistor did not measure 60 ( 5) ohms, then replace the termination resistor.If the measurement at the connector for the termination resistor was not 60 ( 5) ohms, replace the harness or repair the harness.STOPTest Step 4. CHECK THE MACHINE HARNESS
Disconnect the harness connectors from the ECM.
Measure the resistance from contact "J2-45" on the ECM connector to contact "C" on the connector. Note the resistance.
Measure the resistance from contact "J2-46" on the ECM connector to contact "D" on the connector. Note the resistance.Expected Result:The resistance measurements are 60 ( 5) ohms.Results:
YES -