24 General Motors generator fault/alarm codes with symptom, cause and remedy — compiled from General Motors service and controller documentation.
| Code | Meaning / symptom | Cause | Remedy |
|---|---|---|---|
| 10 | Low Oil Pressure Pre-alarm LED | ||
| 11 | Low Fuel LED | Check fuel supply and replenish as required. | |
| 12 | Unit Not In Auto LED | Move the AUTO/OFF/MANUAL switch to the AUTO position for automatic starting. | |
| 13 | Press To Test Button | ||
| 14 | Engine Overheat LED | Reduce load if possible by turning off non-critical loads. Check air inlets and outlets and remove any obstructions to airflow. Open doors or windows in generator area to increase ventilation. | |
| 15 | Engine Overheat Shutdown LED | Allow engine to cool down completely before proceeding with the following checks: Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. Check for obstructions to cooling airflow and correct as necessary. Check for a slipping fan belt and tighten if loose. | |
| 16 | Low Oil Pressure LED | Check oil level, lines and filters. If the oil system is okay but oil level is low, replenish. | |
| 17 | Overcrank LED | Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. Check for dirty fuel filter and replace if necessary (See Maintenance section of Engine Manual). Check for dirty or plugged air filter and replace if necessary (See Maintenance section of Engine Manual). | |
| 18 | Engine Over-speed LED | Refer to governor adjust procedure. Contact your Dealer or Distributor for service. | |
| 19 | Unit Not In Auto LED | Move the AUTO/OFF/MANUAL switch to the AUTO position for automatic starting. | |
| 20 | Low Fuel LED | Check fuel level and replenish as required. See Engine Manual for fuel system priming procedure. | |
| 21 | Low Coolant Temperature LED | Check for the following conditions: Coolant heater not connected to power supply. Check for blown fuse, open circuit breaker or disconnected heater cord and correct as required. Check for low-coolant level and replenish if required. Look for possible coolant leakage points and repair as required. | |
| 22 | Charger Malfunction LED | Check and repair. Contact Dealer or Distributor for assistance. | |
| 23 | Low Battery LED | Check electrolyte level and charger output or replace the battery. | |
| 24 | Fault LED on but no fault exists. Engine gauges show oil pressure, engine temperature, and frequency (speed) are within normal limits. | Contact your Dealer or Distributor for service. | |
| 25 | Engine Start from Generator Control Panel but will not start automatically or from a remote panel. | Check the following: Check wire to ATS. See ATS section for further troubleshooting. Contact your Dealer or Distributor for assistance. | |
| 26 | Engine will not crank. | Check for the following conditions: Fault lamp on. Correct fault and reset control. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. Discharged or defective battery. Recharge or replace the battery. | |
| 27 | No AC Output Voltage. | Verify output with another meter if ok check meter, if ok check meter fuses. Regulator fuse is blown. Replace fuse. Contact your Dealer or Distributor if voltage build-up causes fuse to blow. Check rotating rectifier for damaged diodes. Replace all diodes if any are failed. | |
| 28 | No Engine Start. | Check Engine Start connections. Investigate why the Engine Control Switch was put in Manual. Contact your Dealer or Distributor for assistance. | |
| 29 | No Engine Stop. | Check Engine Start Timer setting. Check Engine Start Connections. Investigate why the Engine Control Switch was put in Manual. Contact your Dealer or Distributor for assistance. | |
| 30 | ATS will not transfer to Emergency. | Check Engine Start connections, Generator output, and Engine Control Switch. Plug in Power Supply harness. Plug in Limit Switch harness. Check transfer to Emergency Timer setting. Contact your Dealer or Distributor for assistance. | |
| 31 | ATS will not transfer to Normal. | Check Utility and Utility breakers. Plug in Power Supply harness. Plug in Limit Switch harness. Check retransfer to Normal Timer setting. Contact your Dealer or Distributor for assistance. | |
| 8 | Low Water Temp LED | ||
| 9 | High Engine Temp Pre-alarm LED |
Compiled from General Motors service manuals and controller documentation. Cause/remedy shown where extracted; always verify against the manual for your exact model.
Low Fuel LED. Remedy: Check fuel supply and replenish as required..
Unit Not In Auto LED. Remedy: Move the AUTO/OFF/MANUAL switch to the AUTO position for automatic starting..
Engine Overheat LED. Remedy: Reduce load if possible by turning off non-critical loads. Check air inlets and outlets and remove any obstructions to airflow. Open doors or windows in generator area to increase ventilation..
Engine Overheat Shutdown LED. Remedy: Allow engine to cool down completely before proceeding with the following checks: Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. Check for obstructions to cooling airflow and correct as necessary. Check for a slipping fan belt and tighten if loose..
Low Oil Pressure LED. Remedy: Check oil level, lines and filters. If the oil system is okay but oil level is low, replenish..
Overcrank LED. Remedy: Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. Check for dirty fuel filter and replace if necessary (See Maintenance section of Engine Manual). Check for dirty or plugged air filter and replace if necessary (See Maintenance section of Engine Manual)..
Engine Over-speed LED. Remedy: Refer to governor adjust procedure. Contact your Dealer or Distributor for service..
Unit Not In Auto LED. Remedy: Move the AUTO/OFF/MANUAL switch to the AUTO position for automatic starting..
Low Fuel LED. Remedy: Check fuel level and replenish as required. See Engine Manual for fuel system priming procedure..
Low Coolant Temperature LED. Remedy: Check for the following conditions: Coolant heater not connected to power supply. Check for blown fuse, open circuit breaker or disconnected heater cord and correct as required. Check for low-coolant level and replenish if required. Look for possible coolant leakage points and repair as required..
Charger Malfunction LED. Remedy: Check and repair. Contact Dealer or Distributor for assistance..
Low Battery LED. Remedy: Check electrolyte level and charger output or replace the battery..
Fault LED on but no fault exists. Engine gauges show oil pressure, engine temperature, and frequency (speed) are within normal limits.. Remedy: Contact your Dealer or Distributor for service..
Engine Start from Generator Control Panel but will not start automatically or from a remote panel.. Remedy: Check the following: Check wire to ATS. See ATS section for further troubleshooting. Contact your Dealer or Distributor for assistance..
Engine will not crank.. Remedy: Check for the following conditions: Fault lamp on. Correct fault and reset control. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. Discharged or defective battery. Recharge or replace the battery..
No AC Output Voltage.. Remedy: Verify output with another meter if ok check meter, if ok check meter fuses. Regulator fuse is blown. Replace fuse. Contact your Dealer or Distributor if voltage build-up causes fuse to blow. Check rotating rectifier for damaged diodes. Replace all diodes if any are failed..
No Engine Start.. Remedy: Check Engine Start connections. Investigate why the Engine Control Switch was put in Manual. Contact your Dealer or Distributor for assistance..
No Engine Stop.. Remedy: Check Engine Start Timer setting. Check Engine Start Connections. Investigate why the Engine Control Switch was put in Manual. Contact your Dealer or Distributor for assistance..