CAT Standby Generators Error Codes

E-01

Generator will not start, controller displays E-01 and inhibits crank

Emergency Stop Active / E-Stop Circuit Open

E-02

Generator cranks but does not start, controller shows E-02

Low Fuel Pressure / Fuel Supply Fault

E-03

Generator shuts down shortly after start, E-03 displayed

Low Oil Pressure Shutdown

E-04

Generator will not crank, controller shows E-04

Low Battery Voltage / Battery Under-Voltage Lockout

E-05

Generator cranks but fails to start, E-05 displayed on controller

Overcrank / Failed to Start

E-06

Generator shuts down during run, controller shows E-06

High Engine Coolant Temperature Shutdown

E-07

Generator shuts down, controller displays E-07

Overspeed Shutdown

E-08

Generator shuts down, E-08 displayed, no AC output to load

Underspeed / Underfrequency Shutdown

E-09

Generator shuts down, controller shows E-09, engine temperature normal

High Exhaust Temperature / Turbocharger Overheat

E-10

Generator shuts down, controller displays E-10, oil level appears normal

Low Oil Level / Oil Level Sensor Fault

E-11

Generator shuts down, controller shows E-11, coolant level normal

Low Coolant Level Sensor Fault / Coolant Loss

E-12

Generator will not transfer load, controller shows E-12

Generator Undervoltage / Low Output Voltage

E-13

Generator trips on E-13, load drops, controller indicates overvoltage

Generator Overvoltage

E-14

Generator shuts down, controller shows E-14, no obvious engine issue

Generator Overcurrent / Overload Trip

E-15

Controller displays E-15, generator will not start automatically

Remote Start Signal Fault / ATS Communication Error

E-16

Controller shows E-16, engine stops, no other obvious alarms

Emergency Shutdown Input Active (External Fault)

E-17

Controller displays E-17, no engine crank when start is commanded

Starter Circuit Fault / Crank Relay Failure

E-18

Controller shows E-18, generator runs but alarms, possible sensor issues

Analog Sensor Out of Range / Sensor Calibration Fault

E-19

Controller displays E-19, generator will not start, fuel tank is full

Fuel Level Sensor Fault / High or Low Fuel Alarm

E-20

Controller shows E-20, generator stops, no obvious mechanical problem

Controller Internal Fault / Memory Error

Symptom

Corrosion and rust visible on generator frame, fuel tank, and electrical connections

Environmental Corrosion / Moisture Ingress

Symptom

Generator battery repeatedly goes dead between exercise cycles

Chronic Battery Discharge / Charging System Issue

Symptom

Generator controller display is blank or unreadable, unit otherwise appears intact

Controller Power Loss / Display Failure

Symptom

Generator emits blue smoke and consumes engine oil

Oil Burning / Internal Engine Wear

Symptom

Generator emits visible black smoke from the exhaust during operation

Rich Fuel Mixture / Incomplete Combustion

Symptom

Generator emits white smoke, especially on startup, and runs rough

Incomplete Combustion / Coolant or Fuel Issue

Symptom

Generator enclosure fills with rodents or insects, causing chewed wires and nests

Pest Intrusion / Wiring Damage

Symptom

Generator enclosure is very hot to the touch, components show heat discoloration

Inadequate Ventilation / Cooling Airflow Restriction

Symptom

Generator fails to start automatically during a utility outage but starts manually

Auto Start Logic / Scheduling Fault

Symptom

Generator is excessively noisy during operation compared to normal

Abnormal Mechanical Noise / Exhaust or Engine Mount Issue

Symptom

Generator runs but frequency is low or high (not 50/60 Hz as expected)

Incorrect Engine Speed / Governor Misadjustment

Symptom

Generator runs but house lights flicker and some equipment resets intermittently

Unstable Voltage / Poor Voltage Regulation

Symptom

Generator starts and runs but does not transfer power to the house or building

Automatic Transfer Switch (ATS) Fails to Transfer

Symptom

Generator starts and runs only during exercise but not during real power outages

ATS Sensing or Logic Fault

Symptom

Generator starts and then immediately shuts down without any code on a basic panel

Run Relay or Fuel Solenoid Drops Out

Symptom

Generator vibrates excessively, causing enclosure panels to rattle

Excessive Vibration / Misalignment

Symptom

Strong fuel smell around the generator during or after operation

Fuel Leak / Fuel System Integrity Issue

Symptom

Visible oil leak under or around the generator set

Engine Oil Leak