General Motors 4.3L troubleshooting: 35 fault codes and 16 symptom-cause-remedy entries from the manufacturer's own service documentation.
General Motors 4.3L — full specs, parts & maintenance.
All General Motors fault codes →
| Code | Meaning | Remedy |
|---|---|---|
| #14 | PRE-HI ENGINE TEMP LED. Engine continues to operate — Indicates engine has begun to overheat and engine temperature has risen to approximately 215°F (105°C). If generator is powering non critical and critical loads and cannot be shut down. Use the following: | 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; If engine can be stopped, follow procedure in Step 2 |
| 2 | HI ENGINE TEMP LED. Engine shuts down — Indicates engine has overheated (engine temperature has risen above 225°F/110°C) or coolant level is low (sets with coolant level sensor). | 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; Reset control and restart after locating and correcting problem. Contact your Dealer or Distributor if none of the above |
| *3 | PRE LOW OIL PRESSURE LED. Engine continues to operate — Indicates engine oil pressure has dropped to 20 psi (138kPa). If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow Step 4 procedure. If engine can be stopped, follow procedures in Step 4. | |
| 4 | LOW OIL PRESSURE LED. Engine shuts down — Indicates engine oil pressure has dropped to 15 psi (97kPa). NOTE: See also Step 5 | Check oil level, lines and filters. If oil system is okay, but oil level is low, replenish. Reset control and restart. Contact your Dealer or Distributor if oil pressure is not in the range of 35 to 55 psi (21 to 379 kPa) |
| 5 | OVERCRANK LED. Engine stops cranking. Or Engine runs, shuts down, and LOW OIL PRESSURE LED — Indicates possible fuel system problem. | 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); Refer to Step 4; Reset the control and restart after correcting the problem. Contact your Dealer or Distributor for service if none of the above |
| 6 | Engine runs and then shuts down, OVERSPEED LED — Indicates engine has exceeded normal operating speed. | Refer to governor adjust procedure. Contact your Dealer or Distributor for service |
| *7 | UNIT NOT IN AUTO LED — Indicates AUTO/OFF/MANUAL switch is in the OFF position which will prevent automatic starting if an automatic transfer switch is used. | Move the AUTO/OFF/MANUAL switch to the AUTO position for automatic starting |
| 8 | LOW FUEL LED. Engine continues to run — Indicates diesel fuel supply is running low. | Check fuel supply and replenish as required |
| *9 | LOW FUEL LED. Engine shuts down and LOW OIL PRESSURE LED — Indicates engine has run out of fuel. | Check fuel level and replenish as required. See Engine Manual for fuel system priming procedure |
| *10 | LOW ENGINE TEMPERATURE LED. Set is in standby mode but not operating — Indicates engine coolant heater is not operating or is not circulating coolant. | 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; Contact your Dealer or Distributor if none of the above |
| *11 | CHARGER MALFUNCTION LED. Unit continues to run — Indicates possible fault with the battery charging system. If LED is on only when unit is running indicated problem with battery charging alternator. | Check and repair. Contact Dealer or Distributor for assistance |
| *12 | LOW BATTERY LED — Indicates starting battery voltage is low. | Check electrolyte level and charger output or replace the battery |
| 13 | FAULT LED on but no fault exists. Engine gauges show oil pressure, engine temperature, and frequency (speed) are within normal limits — The monitor board or a sensor may be at fault. | Contact your Dealer or Distributor for service |
| 14 | Engine starts from generator control panel, but will not start automatically or from a remote panel. (Note: The AUTO/OFF/MANUAL switch must be in the AUTO position for automatic or remote starting) — Indicates possible fault with remote start circuit. | Check the following: Check wire to ATS; See ATS section for further troubleshooting; Contact your Dealer or Distributor for assistance |
| 15 | Engine will not crank — Indicates possible fault with control or starting system. | 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; Contact your Dealer or Distributor for assistance if none of the above |
| 16 | No AC output voltage — Indicates possible fault | |
| 9 | High Engine Temp Pre-alarm LED | |
| 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. |
| 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. |
| Symptom | Cause | Remedy |
|---|---|---|
| Blown Fuse on Terminal #1 | Shorted leads when hooking up or overloaded circuits | Replace fuse with 9 amp fuse |
| Low Battery Voltage at Start | Defective battery; Charger not functioning; Corroded or loose battery connection | |
| FAIL TO CRANK | If voltage is present at starter solenoid, may have defective starter or solenoid. If no voltage at starter solenoid, may have open leads to solenoid | |
| FAIL TO CRANK — Terminal #7 | If present, check for voltage source. There should be no voltage present | |
| FAIL TO CRANK — Unused Terminal #5 | Terminal #5 should be connected to the KASSEC Terminal #9, ground, when not in use or it may prevent unit from starting | |
| FAIL TO CRANK — Failure Lights | Unit will not crank if any failure lamps are on | Correct failure before trying to start |
| UNIT DOES NOT START — Fuel Supply | Empty fuel tank; Air in fuel lines; Wrong pressure on Natural Gas or LPG | |
| UNIT DOES NOT START — Voltage on Terminal #2 While Cranking | If present may have defective fuel valve, defective ignition system or loose connection | |
| UNIT WILL START THEN FAIL — Loss of Fuel | Empty fuel tank; Restricted fuel filter; Restricted, broken or loose fuel line | |
| UNIT WILL START THEN FAIL — Overcrank light lit | Lost signal on Mag Pickup Crank Disconnect Terminal or lost signal on Auxiliary Crank Disconnect terminal after unit started | |
| UNIT WILL START THEN FAIL — Low Oil light lit | Low oil in crankcase; Oil pump failed; Defective pressure switch | |
| UNIT WILL START THEN FAIL — High Water Temperature light lit | Low water level in radiator; Thermostat closed; Broken fan belt; Restricted flow through radiator; Ambient temperature too high; Defective temperature switch | |
| UNIT WILL START THEN FAIL — Overspeed light lit | Lost governor control; Defective overspeed switch | |
| UNIT WILL START THEN FAIL — Loose or Open Connections | May have lost power to control or ignition system | |
| UNIT STARTS BUT STARTER DOES NOT DISENGAGE — Voltage on Terminal #3 After Unit Running | Signal must be present at either Terminal #5, 6, 7, or 12 after unit starts to operate crank disconnect of control | |
| UNIT STARTS BUT STARTER DOES NOT DISENGAGE — No Voltage on Terminal 49 After Unit is Running | Starter drive could be hanging up or the solenoid on starter is not disengaging |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Shorted leads when hooking up or overloaded circuits. See the table for the matching fixes.
Documented causes: Defective battery; Charger not functioning; Corroded or loose battery connection. See the table for the matching fixes.
Documented causes: If voltage is present at starter solenoid, may have defective starter or solenoid. If no voltage at starter solenoid, may have open leads to solenoid. See the table for the matching fixes.