BODY AS-PISTON 3466618 - Caterpillar

Illustration 1 g02098356
Connections of the position sensor for the left steering cylinder
Illustration 2 g01254278
(1) Left steering cylinder (2) Right steering cylinder (3) Connector for steering position sensor on the back side of the cylindersThis diagnostic code is associated with the position sensor for the left steering cylinder. The position sensor provides a PWM input signal to the Implement ECM 2 and to the Transmission/Chassis ECM.The FMI 01 diagnostic code is activated when the ECM receives a valid signal from the sensor, but the signal is below the low limit of the expected signal range.The sensor is a PWM sensor that operates at a frequency of approximately 500 Hz. The duty cycle of the PWM signal that is 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 is unlikely.Note: The Transmission/Chassis ECM (MID 027) and the Implement ECM 2 (MID 145) receive an input signal from the position sensor of the left steer cylinder. Both of the electronic control modules can activate a CID 2200 FMI 01 diagnostic code when the signal is below the normal range.
If one ECM has activated a CID 2200 FMI 01 diagnostic code and the other ECM has not activated the diagnostic code, it is likely that the sensor is operating correctly. When this occurs, a poor connection in the machine harness would be suspected.
When both of the electronic control modules have activated the diagnostic code, either the sensor or a harness problem could be the cause.
If both the electronic control modules have activated the diagnostic code, it is unlikely that either ECM is causing the problem.
For either condition, proceed with this procedure