CAT Standby Generators Error Codes

E-01

Generator will not start; the controller displays E-01 and inhibits cranking.

Emergency Stop Active / E-Stop Circuit Open

E-02

Generator cranks but does not start; the 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 the 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; the 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 roughly.

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 house lights flicker and some equipment resets intermittently.

Unstable Voltage / Poor Voltage Regulation

Symptom

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

Incorrect Engine Speed / Governor Misadjustment

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