John Deere 3353.31 – ECU: No Alternator Condition Exists

The control software has detected that the alternator is either not being driven or its output voltage has remained low for greater than 10 seconds. This means the machine's electrical system is not receiving a charge, which will eventually result in a loss of machine availability or limited software functionality.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 5065M
• 5075M
• 5085M
• 5105ML
• 670G
• 672G
• 770G
• 772G
• 870G
• 872G
• 444K
• 524K
• 544K
• 624K
• 724K
• 744K
• 824K
• 844K
• 250D
• 260E
• 300D
• 310E
• 2154D
• 2454D
• 3154G
• 7400A TerrainCut
• 7760 Cotton Pickers

1. 1

   Determine if the DTC periodically goes away to rule out a loose connection versus a hard failure

2. 2

   Check the alternator drive belt to ensure the alternator is being physically driven and the belt is not broken, worn, or slipping

3. 3

   Inspect the alternator wiring harness for an open or bad connection, verify the smart regulator signal frequency, and ensure there are no broken wires between the alternator and the ECU

4. 4

   Verify the voltage output at the vehicle controller to confirm the alternator output is genuinely low

1. 1

   Inspect the Drive Belt

   Locate the alternator drive belt. If the belt is broken, heavily worn, or damaged, replace the drive belt and verify proper tension.

2. 2

   Inspect the Wiring

   If the belt is intact and driving the alternator pulley properly, inspect the electrical connections at the alternator. Clean any corroded terminals and repair any open circuits or shorts in the wiring harness.

3. 3

   Replace the Alternator

   If the belt is functioning correctly and the wiring is intact, but the alternator is still failing to produce the required voltage (or the smart regulator has failed internally), the alternator itself is defective and must be replaced.

4. 4

   Clear Codes

   After replacing the belt or alternator, start the engine and verify that the charging system is operating at the correct voltage. Clear the 003353.31 code from the ECU.