BOGIE AS-MIDDLE 9W0662 - Caterpillar

Illustration 1 g02359871
Schematic of the direction selector #2 position sensor #1
The CID 3377 diagnostic code is associated with direction selector #2 position sensor #1. The signal receives power from thetransmission ECM. The position sensor sends a PWM input signal to thetransmission ECM. The duty cycle of the signal should be 80% to 95% in the forward position and 5% to 20% in the reverse position. In neutral position the duty cycle should be within 40% to 60%. The position sensor is a PWM sensor that operates at a frequency of approximately 500 40 Hz.The FMI 08 diagnostic code means that the input signal from the sensor is not within the expected range.The possible causes of this condition are listed below:
The signal circuit is shorted to the +battery or shorted to ground intermittently.
The signal circuit is open intermittently or the sensor is disconnected.
The sensor may have failed.
The ECM may have failed. The ECM failing is unlikely.System Response:The machine response is listed below:
A level 2 warning will be generated.
All functions that are involved in the pitch of the blade are disabled.
The "Limp Home" option is still available.Note: This diagnostic code is usually an intermittent condition. The diagnostic code may be active or the diagnostic code may not be active.Note: This procedure may cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the procedure is completed, clear the created diagnostic codes.Test Step 1. CHECK FOR POWER AT THE SENSOR.
Do not disconnect the harness connector from the sensor.
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along contact 1 (wire J850-WH(White)) for the voltage supply.
Turn the key start switch and the disconnect switch to the ON position. Do not start the engine.
Measure the voltage from contact 1 (wire J850-WH(White)) to contact 2 (wire J764-BR(Brown)). Expected Result:The voltage is 8 VDC.Results:
OK - The voltage is 8 VDC. Proceed to Test Step 3.
NOT OK - The voltage is not 10 VDC. The circuit is open. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT OF THE SENSOR.
Turn the key start switch and the disconnect switch to the OFF position.
At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from contact 1. Insert the probe along the signal wire (contact 3).
At the back of the harness connector for the sensor, insert the 7X-1710 Multimeter Probe along the ground wire (contact 2).
Turn the disconnect switch and the key start switch to the ON position.
Monitor the signal of the sensor with the 146-4080 Digital Multimeter.
Without disconnecting the sensor or the hardware that is associated with the sensor from the machine, take the sensor through the full operating range. Expected Result:The sensor signal responds in the manner that is described at the beginning of this procedure.Results:
OK - The sensor signal responds correctly. The sensor is operating correctly. Proceed to Test Step 3.
NOT OK - The sensor signal does not respond correctly. The