BONNET 3636815 - Caterpillar

MID 087 - Chassis ECMCID 1175 - Body Position SensorFMI 03 - Voltage Above Normal
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Body position sensor circuit
This diagnostic code indicates the "Chassis" ECM detects the body position sensor signal voltage is above normal.The following can cause this code:
Failed power circuit
Failed ground
Sensor failure
Sensor mechanical linkage has failed
Failed signal circuit
ECM failureThe following test procedure may create other diagnostic codes. Ignore these created codes and clear these created codes after the original diagnostic code has been corrected. Ensure CID 1175 FMI 03 is active before performing this procedure.System Response:
Incorrect position of the dump body gauge reading.Test Step 1. CHECK FOR BATTERY VOLTAGE AT THE SENSOR
Turn on the disconnect switch and the key switch.
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe into contact A.
At the back of the harness connector for the sensor, insert the other probe into contact B.
Measure the voltage.Expected Result:The voltage is between 18 VDC and 24 VDC.Results:
OK - The voltage is between 18 VDC and 24 VDC. Proceed to Test Step 2.
NOT OK - The voltage is 0 VDC. The Chassis fuse has failed.Repair: Replace the fuse.STOP
NOT OK - The voltage is more than 0 VDC but less than 18 VDC. Proceed to Test Step 7.Test Step 2. CHECK FOR A PROPER ELECTRICAL GROUND AT THE SENSOR
Ensure that the harness is still connected to the sensor.
Turn off the key switch and the disconnect switch.
Move the 7X-1710 Multimeter Probe from contact A on the harness for the connector to a ground.
Measure the resistance from contact B to ground.Expected Result:The resistance is less than or equal to 1 ohm.Results:
OK - The resistance is less than or equal to 1 ohm. Proceed to Test Step 3.
NOT OK - The resistance is greater than 1 ohm. The harness has failed.Repair: Repair or replace the harness.STOPTest Step 3. INSPECT THE MECHANICAL LINKAGE NEAR THE SENSORPerform the Testing and Adjusting procedure for the body position sensor for the model of truck that is serviced.Expected Result:The mechanical linkage is operating properly.Results:
OK - The mechanical linkage is operating properly. Proceed to Test Step 4.
NOT OK - The mechanical linkage is not operating properly.Repair: Repair the mechanical linkage.STOPTest Step 4. TEST THE DUTY CYCLE OF THE BODY POSITION SENSORUse Cat® Electronic Technician (Cat® ET) to perform this test. For more information about Cat ET, see Troubleshooting, "Service Tools".Note: This test is performed with the body in the DOWN position.
Turn on the disconnect switch and the key switch.
Ensure that the body is down completely.
Check the sensor duty cycle with Cat ET.
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List of ECMs on screen
Select the "Chassis" ECM from Cat ET.
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Status tool screen
Click the "Status" icon to view the status.
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Hoist sensor screen
View the information for the body position sensor duty cycle.Expected Result:The body position sensor duty cycle is less than 98%.Results:
OK - The duty cycle is less than 98%. Proceed to Test Step 5.
NOT OK - The duty cycle is greater than 98%. Proceed to Test Step 5.Test Step 5. TEST THE SENSOR OUTPUT