Where can I find a list of portable generator fault codes and basic troubleshooting steps?

This article provides a guide to portable generator fault codes and their meanings. It discusses the function of the Malfunction Indicator Lamp (MIL), shut-down fault codes, active fault codes, and fault code memory and provides a list of common codes. 

Note: Your owner's manual also has a list of portable generator fault codes. 

 

Environment

This article applies to portable generators GP15500EFI and GP18000EFI. 

 

Table of contents

• What is the Malfunction Indicator Lamp (MIL)
• How does the MIL operate? 
• Fault code - shutdown
• Fault code - warnings
• Fault code history
• Fault code identification and troubleshooting table

 

 

Malfunction Indicator Lamp (MIL)

The MIL, located on the control panel, indicates when there is a fault in the engine system. The fault lamp displays a 2-digit code by flashing a sequence of long and short flashes. Long flashes last 1.2 seconds, and short flashes last 0.25 seconds.

 

MIL ICONs 

• Condition 1: MIL is not lit, engine and key are OFF
• Condition 2: MIL is dimly illuminated, constant on (not flashing). This indicates the engine control system is running properly (i.e., no fault) (A). 
• Condition 3: MIL is brightly illuminated and flashing. This indicates there is a fault with the engine control system. (B)
  
  

 

MIL operation 

• When the key is switched ON, the MIL will illuminate for 0.5 seconds (this does not indicate a fault). 
• If multiple failures have been detected, the MIL will pause between fault codes for two (2) seconds. 
• Once the MIL has flashed all failure codes, it will pause for five (5) seconds and then reappear the code. The lamp will continue to repeat the codes until they are no longer active or the key is switched OFF. 
• Once the fault(s) have been resolved, the codes will be saved in the Engine Control Modules (ECM) fault history memory. 

 

Active fault codes - Shutdown 

If a fault that requires stopping the unit has been detected, the engine will automatically stop (or will not start ), and the lamp will flash the active fault code. Before the unit can be started, the key must be first turned to the OFF position to clear the active fault. The fault code will be saved in the fault history memory when the key is switched off. 

 

Active fault code - Warning

If a fault has been detected but does not require stopping the unit, the MIL will flash the fault code as long as the fault is present. If the fault is no longer present, the lamp will stop flashing, and the fault code will be saved in the fault history memory. 

 

Fault history memory

The ECM will store a list of faults for three (3) ON-OFF key cycles. To view previous faults, turn the key to the ON position, and do not start the engine. After 30 seconds, the MIL will flash previous faults stored in memory. The fault codes will be displayed with a flashing sequence similar to active faults. When the list is completed, it will restart at the beginning. To stop the sequence, either switch the key OFF or start the engine. 

 

Fault code identification and troubleshooting table

Example code 6-1 is displayed by: 6 long blinks - 6, one-second pause, one short blink = 1 

Note: This table provides common fault codes and is for informational purposes only. For a complete list of error codes, contact a Generac Independent Authorized Service Dealer (IASD). 

 

Fault Code	Cause	Condition	Correction
1-1	Co Monitor	1. Carbon Monoxide above the limit. 2. Input voltage to module below the normal range.	1. Never run a generator indoors or in a partially enclosed area. Move the generator.  2. Contact Generac IASD.
1-2	Battery voltage	1. Battery voltage above normal operating range.	1. Contact Generac IASD.
1-3	Battery Voltage	1. Battery voltage below normal operating range.	1. Charge the battery to the correct level.
5-2	Engine Speed	1. No or low fuel.  2. Engine speed below normal operating range.	1. Fil fuel tank.  2. Contact Generac IASD
6-1	Engine Oil Pressure	1. Low oil pressure.  2. Switch voltage not detected.	1. Fill the crankcase to the correct level.  2. Contact Generac IASD.
Other	Multiple	Multiple	Contact Generac IASD