CABLE THROTT 0776381 - Caterpillar

Operation Description:The following diagnostic function should be used if the transmission is in AUTO mode. Perform the diagnostic function if the transmission does not shift and no diagnostic code is shown.Test Step 1. CHECK THE OPERATION OF THE AUTO/MANUAL SWITCH
Turn the key start switch to the ON position.
Measure the voltage from contact 3 to contact 2 (ground) while the position of the AUTO/MANUAL switch is changed.
Measure the voltage from contact 1 to contact 2 (ground) while the position of the AUTO/MANUAL switch is changed.Expected Result:The voltage should change from +5 DCV to 0 Volts as the position of the switch changes.Results:
OK - The voltage changes as the position of the switch changes. The AUTO/MANUAL switch and the machine harness are correct. Stop.
NOT OK - The voltage does NOT change as the position of the switch changes. The harness is incorrect or the switch is incorrect. Proceed to test step 2.Test Step 2. CHECK THE MACHINE HARNESS
Remove the machine harness from the switch.
Measure the voltage at the terminal of the AUTO/MANUAL switch (wire 973-BR and 977-YL).
Check for continuity between switch contact 2 and Ground.Expected Result:The voltage should be +5 DCV on each of the wires, and continuity should exist.Results:
OK - The voltage on each of the wires is not correct, or continuity does not exist. The AUTO/MANUAL switch is correct. The machine harness has failed.Repair: Repair the machine harness or replace the machine harness. Stop.
NOT OK - The voltage on each of the wires is correct and continuity exists. The AUTO/MANUAL switch has failed.Repair: Replace the AUTO/MANUAL switch. Stop.