BARREL AS 2478709 - Caterpillar

Illustration 1 g02728734
Connections of left steering cylinder position sensor
This diagnostic code is associated with the left steering cylinder position sensor. The position sensor provides a PWM signal to the Steering ECM and to the Transmission ECM. The FMI 0 diagnostic code is activated when the ECM receives a valid signal from the sensor, that is above the high limit expected for the signal range.The sensor is a PWM sensor that operates at a frequency of approximately 500 Hz. The duty cycle of the PWM signal supplied to the ECM is measured in small increments. The changes in the duty cycle of the sensor cannot be measured with a digital multimeter.The following conditions could cause this diagnostic code to be activated:
Mechanical devices are broken or loose.
The sensor has failed.
The ECM has failed. An ECM failure unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections are often the cause of a problem in an electrical circuit. Inspect the connections for the following:
Connections are clean.
Connections are secure.
Connections are in good condition.If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.Note: The following test procedure may create other diagnostic codes. Clear the diagnostic codes when the original diagnostic code has been corrected.Test Step 1. CHECK THE MECHANICAL CONNECTIONS
Turn the disconnect switch to the OFF position.
Turn the key start switch to the OFF position.
Visually inspect the mechanical connections for the left steering cylinder. Verify the following:
All mechanical connections and adjustments for the steering cylinder are in good condition.
None of the mechanical connections are loose.Expected Result:All mechanical connections for the steering cylinder are in good condition and no mechanical connections are loose.Results:
OK - All mechanical connections for the steering cylinder are correct. Proceed to Test Step 2.
NOT OK - All mechanical connections for the steering cylinder are not correct.Repair: Perform the maintenance required to correct the problem with the mechanical connections for the steering cylinder. After the problem has been corrected, verify that this diagnostic code is still active before proceeding with this procedure.STOPTest Step 2. CHECK THE SENSOR
Turn the disconnect switch to the OFF position.
Turn the key start switch to the OFF position.
Do not start the engine when performing this step. If the engine is started, any change in steering wheel position will result in a change to maximum wheel angle. Steering to maximum wheel angle may result in severe injury or death.
Fabricate six jumper wires long enough to jumper the left steering cylinder position sensor to the harness for the right steering cylinder position sensor.
Jumper the left steering cylinder position sensor connector to the right steering cylinder position sensor harness.
Jumper the right steering cylinder position sensor connector to the left steering cylinder position sensor harness.
Turn the disconnect switch to the ON position.
Turn the key start switch to the ON position.Note: Do not start the engine.
Observe the status of the active diagnostic code for the left steering sensor.Expected Result:When the harness connectors are switched,