ALTERNATOR GP-CHARGING 3785308 - Caterpillar

Illustration 1 g01391924
Schematic for the Transmission Range Select SwitchNote: Some publications may refer to this as the "Upshift/Downshift" switch.This diagnostic code is associated with the Transmission Range Select Switch. The Transmission Range Select Switch has two momentary inputs to the ECM. The two inputs are normally open. During normal operation, both of the inputs is open. When a circuit is measured with a voltmeter, an open circuit will measure approximately 13 VDC to ground and a closed circuit will measure approximately 0 VDC to ground. An FMI 04 diagnostic code is recorded when both of the inputs are grounded.Conditions that could cause this diagnostic code to be activated are listed below:
The "normally open" signal circuit (wire P991-PK) is always shorted to ground.
The "normally open" signal circuit (wire F774-WH) is always shorted to ground.
The switch has failed.
The ECM has failed. This is unlikely. Note: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, that all connections are secure and that all connections are in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes. Clear any created diagnostic codes after the original diagnostic code has been corrected.System Response:A Level 2 warning is generated.The last known gear will be maintained. If the Diagnostic Code is present at "Key On", the machine will default to Gear 2 when in low gear.Test Step 1. CHECK THE SWITCH
Check for continuity between contact 1 and contact 2 of the switch.
Press the switch and hold the switch while checking the switch for continuity.
Check for continuity between contact 3 and contact 2 of the switch.
Press the switch and hold the switch while checking for continuity.Expected Result:While checking the circuit for continuity the technician observes a low level of resistance across the contacts. The observed resistance should be around 5 ohms or less.Results:
OK - While checking the circuit for continuity, the technician observes a low level of resistance across the contacts. The observed resistance should be around 5 ohms or less. Proceed to Test Step 2.
NOT OK - While checking the circuit for continuity the technician observes a high level of resistance across the contacts. The observed resistance should be around 5000 ohms or greater. The switch has failed.Repair: Temporarily connect a new "Transmission Range Select Switch" to the harness. Do not install the switch. Verify that the replacement switch has cleared the CID 1711 FMI 04 code. If the code is no longer active, permanently install the new Transmission Range Select Switch.Verify that there are no active diagnostic codes for the "Transmission Range Select Switch". Clear any logged diagnostic codes.STOPTest Step 2. CHECK THE SIGNAL CIRCUITS FOR A SHORT TO GROUND
The switch remains disconnected from the machine harness.
Turn the starter