FAN AS 2112742 - Caterpillar

Illustration 1 g00568117
(1) Safety cables.
Illustration 2 g00568120
(2) Body Position sensor. (3) Body Position sensor buffer.
The Body Position sensor (2) and the Body Position sensor buffer (Legacy) (3) are located under the truck dump body behind the rear axle housing on the left hand side of the machine.
Illustration 3 g02110915
Schematic Of The Body Position Sensor
Illustration 4 g00568215
Schematic Of The Body Position Sensor with a buffer (Legacy)
This diagnostic code is associated with the Body Position sensor. This diagnostic code is recorded when the Chassis Electronic Control Module (ECM) reads a PWM signal from the sensor that has an abnormal frequency, pulse width or pulse period.Note: This diagnostic code is usually an intermittent condition. The diagnostic code may be active or the diagnostic code may not be active.The possible causes of this condition are listed:
The sensor may have failed.
The ECM may have failed.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 1175 FMI 08 is active before performing this procedure.System Response:The Body Snub function for the hoist system does not operate properly when the body is lowered. The gear of the machine is limited. The gear is limited to the current setting for the Gear Limit function. The hoist system will operate properly after the diagnostic code has been corrected.Test Step 1. CHECK THE OPERATION OF THE SENSOR.The output frequency of the sensor is approximately 500 Hz. The duty cycle of the signal varies as the position sensor moves.
Turn the battery disconnect switch and the key start switch to the ON position.
Ensure that the frequency of the PWM signal from the sensor is between 400 HZ and 600 HZ.
Ensure that the diagnostic code is active.
Disconnect the machine harness from the sensor. Expected Result:The diagnostic code is no longer active.Results:
OK - The diagnostic code is no longer active. The sensor has failed.Repair: Replace the sensor. Verify that the new sensor has corrected the diagnostic code.STOP
Not OK - The diagnostic code remains active. The sensor is not the cause of the diagnostic code. The ECM may have failed.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this diagnostic code procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer toTesting and Adjusting, "Electronic Control Module (ECM) – Replace".STOP