TUBE AS 3386050 - Caterpillar

Illustration 1 g02144940
Schematic for the Auto/Manual/VSC switchThis diagnostic code relates to the Transmission Auto/Manual/VSC switch. The switch connects to three ECM inputs. Two contacts are open and one contact is grounded during proper switch operation.An FMI 03 means the ECM has determined that all three of the contacts are open at the same time.Note: The following procedure may create other diagnostic codes. Ignore those diagnostic codes now, but clear those codes after the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0368 FMI 03 is active before performing this procedure.
Table 1
Auto/Manual/VSC Switch Status    
Switch
Position    Manual
J1-27    Auto
J1-26    Variable
Shift
Control
J1-28    
Manual     Closed     Open     Open    
Auto     Open     Closed     Open    
Variable Shift Control (VSC)     Open     Open     Closed    Note: On the switch, the ground signal (202-BK) at pin 5 is only enabled if the switch is in the AUTO or VSC position. The ground signal at contact 5 is not enabled in the MANUAL position.Note: ECM input pinsJ1-26, J1-27, and J1-28 are all Switch-to-Ground inputs that are designed to have a Pull-Up voltage when sensing an open input condition. A short to a voltage source on this type of input lines can also trigger this diagnostic code. Test Step 1. CHECK THE SWITCH CIRCUITS FOR A SHORT TO THE +BATTERY CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
Disconnect the following contacts from the Auto/Manual/VSC switch: 1, 2, 4 and 6.
At the machine harness connector for the ECM, one at a time, measure the resistance first from contact J1-26 (wire 977-YL), next from contact J1-27 (973-BR), and last from contact J1-28 (M998-OR) of the machine harness, each to all the other contacts that are used in the J1 machine harness connector for the ECM.Expected Result:Each measurement is greater than 5000 ohms.Results:
OK - Each measurement is greater than 5000 ohms. The harness is correct. Proceed to Test Step 2.
NO - One or more of the measurements were less than 5 ohms. There is a short in the machine harness.Repair: The short is between wire 977-YL and the circuit with the lowest resistance measurement, wire 973-BR and the circuit with the lowest resistance measurement, or the short is between wire M998-OR and the circuit with the lowest resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE OPERATION OF THE SWITCH
The key start switch and the disconnect switch remain in the OFF position.
The J1 machine harness remains disconnected from the ECM and contacts 1, 2, 4 and 6 remain disconnected from the switch.
Place the switch in the MANUAL position.
Connect one multimeter lead to contact 2 (202-BK) of the switch.
One at a time, connect the other lead from