BOLT 1003205 - Caterpillar

Illustration 1 g03326602
Schematic of the left and right steering lever position sensors
The CID 677 diagnostic code is associated with the right track steering lever position sensor. The FMI 08 diagnostic code is activated when the ECM determines that the signal frequency or pulse width 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 has failed. This condition is unlikely.System Response:Note: Ensure that the diagnostic code is active. This procedure can cause new diagnostic codes to be recorded. Ignore these created problems. When the procedure is completed, clear the created diagnostic codes.Note: The CID 677 FMI 08 diagnostic code may be an intermittent condition.Note: This procedure can 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 A (wire C985-BU(Blue)) for the voltage supply.
Turn the key start switch and the disconnect switch to the ON position.
Measure the voltage from contact A (wire C985-BU(Blue)) to contact B (wire J766-PU(Purple)). 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 8 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 A. Insert the probe along the signal wire (contact C).
At the back of the harness connector for the sensor, insert the 7X-1710 Multimeter Probe along the ground wire (contact B).
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