ALTERNATOR GP 1714257 - Caterpillar

Illustration 1 g00592497
Schematic for Magnetic Switch for the Start RelayThis diagnostic code is recorded when the power train electronic control module (ECM) reads the voltage of the circuit for the start relay as above normal (short to +battery).Possible causes of this diagnostic code are listed:
The harness has failed.
The solenoid is shorted to the +battery.System Response:The machine response is listed:
The shifting for the transmission is disabled.Note: Ensure that the diagnostic code is active and that the diagnostic code indicator is active.Test Step 1. Check the Solenoid.
Turn the key start switch to the OFF.
Disconnect the solenoid with the diagnostic code from the harness.
Turn the key start switch to the ON position.
Place the direction lever in the NEUTRAL position.
At the harness connector for the solenoid, measure the voltage from the power train ECM between contacts 1 and 2.Expected Result:The voltage reading is approximately battery voltage.Results:
YES - The voltage reading is approximately battery voltage. Proceed to test step 2.
NO - The voltage reading is approximately 5 DCV.Repair: The solenoid had failed. Replace the solenoid. Stop.Test Step 2. Inspect the Harness.
Turn the key start switch to the OFF position.
Disconnect the harness from the power train ECM.
Turn the key start switch to the ON position.
At the harness connector for the power train ECM, measure the voltage between contact 2 and the contact for the failed solenoid circuit.Expected Result: The voltage reading should be approximately 0 DCV.Results:
YES - The voltage reading is approximately 0 DCV. Proceed to test step 3.
NO - The voltage is approximately +battery voltage.Repair: There is a short to the +battery in the harness. Repair the harness or replace the harness. Stop.Test Step 3. Check if the Diagnostic Code Remains.
Turn the key start switch to the OFF position.
Inspect all harness connectors and reconnect all harness connectors.
Turn the key start switch to the ON position.
Enter the service mode.
Ensure that the same diagnostic code is active.Expected Result:The same diagnostic code is not active.Results:
YES - The same diagnostic code is not active.Repair: The initial diagnostic code was probably caused by a poor electrical connection at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation. Stop.
NO - The same diagnostic code is active.Repair: It is unlikely that the ECM had failed. Perform the previous steps again. If the cause of the diagnostic code is not found, replace the power train ECM. For more information on replacing the power train ECM, refer to Testing and Adjusting, "Electronic Control Module (Power Train) - Replace". Stop.