LINK & BEARING AS-BUCKET 3561303 - Caterpillar

Illustration 1 g03326546
Schematic of the transmission lever position sensor
The CID 668 diagnostic code is associated with the transmission shift lever. The FMI 12 diagnostic code is recorded when the Power Train ECM detects the signal from the position sensor of the transmission lever is incorrect. The lever has been between the neutral detent range and the forward or reverse detent range longer than is normally required for shifting the transmission.The possible causes of this diagnostic code are listed below:
The detents for the "transmission shift lever" are not functioning properly.
The signal for the "transmission shift lever" is not within the correct range.
The "transmission shift lever" has not been operated properly.System Response:The CID 668 FMI 12 diagnostic code does not allow the transmission shift lever to function until the lever is returned to the Neutral position.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.Test Step 1. CHECK THE OPERATION OF THE DETENTS FOR THE TRANSMISSION SHIFT LEVER
Turn the key start switch to the ON position.
Rotate the transmission shift lever from Neutral to Forward. Then move the lever from Neutral to Reverse. Check that the detents engage smoothly and consistently. Expected Result:The detents engage smoothly and consistently.Results:
OK - The detents engage smoothly and consistently. Proceed to Test Step 2.
NOT OK - The detents do not engage smoothly and consistently.Repair: Repair the detents.STOPTest Step 2. CHECK THE OUTPUT OF THE SENSOR IN THE DETENT POSITIONS
At the back of the harness connector for the sensor, insert the other 7X-1710 Multimeter Probe along the signal wire on contact 3.
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along the ground wire on 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.
View the status of the shift lever position with the Cat Electronic Technician (ET). View the value of the position sensor for the direction lever.
Do not disconnect the sensor or the hardware that is associated with the sensor from the machine. Rotate the transmission shift lever from Neutral to Forward. Then move the lever from Neutral to Reverse. Expected Result:The sensor signal responds in the manner that is described at the beginning of this procedure. The signal is in the correct range on the multimeter and the Cat ET.Results:
OK - The sensor signal responds correctly. The sensor is operating correctly.Repair: Change the operation of the machine. Ensure that the operator fully rotates the direction lever to engage the detents.STOP
NOT OK - The sensor signal does not respond correctly. The sensor is NOT operating correctly.Repair: Replace the sensor.STOP