PISTON AS-CONTROL 9T1705 - Caterpillar

Illustration 1 g01191813
This diagnostic code is associated with the Rotary Switch (Variable Shift Control). The rotary switch is connected to three inputs of the ECM. Two contacts are open and the other contact is grounded during proper operation.This FMI 03 means that the ECM has determined that the normally open contacts and the normally closed contact are open.Note: The following procedure can create other faults that can be detected by the power train ECM. Ignore these created faults and clear the created faults when the fault is corrected. Ensure that the diagnostic code of CID 1521 FMI 03 is active before performing this procedure.
Table 1
Status of the Rotary Switch (Variable Shift Control)    
Switch Position     X972-GR
J2-34     X973-BU
J2-33     X974-BR
J2-32    
VSC #3 (Power)     Ground     Open     Open    
VSC #2 (Mid)     Open     Ground     Open    
VSC #1 (Economy)     Open     Open     Ground    Test Step 1. CHECK FOR AN OPEN CIRCUIT
Turn the disconnect switch and the key start switch to the ON position.
Operate the machine.
Check the status of the CID 1521 FMI 03 while activating and deactivating each position of the auto/manual switch. Note the results. Note: If the code does NOT remain active during operation of the switch, this could indicate a possible open (which corresponds to the switch position) in the harness.
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the machine harness connectors from the power train ECM.
At the machine harness connector for the power train ECM, check the continuity to ground of the open contacts and the grounded contact for each position of the transmission auto/manual switch. Activate and deactivate each position of the transmission auto/manual switch.Expected Result:The continuity checks do not agree with the ground and open combinations.Results:
YES - The continuity checks do NOT agree with the ground and open combinations. The harness or the transmission auto/manual switch is faulty. Proceed to Test Step 2.
NO - The continuity checks agree with the ground and open combinations. Proceed to Test Step 3.Test Step 2. CHECK THE SWITCH.
Disconnect the machine harness from the tRotary Switch (Variable Shift Control).
Check the continuity to ground of the open contacts and the grounded contact for each position of the Rotary Switch (Variable Shift Control). Activate and deactivate each position of the Rotary Switch (Variable Shift Control). Expected Result:The continuity checks do not agree with the ground and open combinations.Results:
YES - The continuity checks do not agree with the ground and open combinations. The Rotary Switch (Variable Shift Control) is faulty.Repair: Repair the switch or replace the switch. Stop.
NO - The continuity checks agree with the ground and open combinations.Repair: Repair the machine harness or replace the machine harness. Stop.Test Step 3. CHECK FOR A SHORT TO THE +BATTERY.
At the machine harness connector for the power train ECM, check the continuity from each switch contact to all contacts for +Battery.Expected Result:Continuity exists between one of the sources of the +Battery voltage and the switch circuit.Results:
YES