ZERO Fridge Check Light Diagnosis Codes

Display “E0” and Check light is solid ON – Temperature sensor issue:

• For temporary use, engage the Emergency Override to operate the fridge freezer.
• Please contact ARB for assistance at your earliest convenience.

Display “E1” and Check light flashes once every 4 seconds – Low supply voltage:

The battery protection system has turned the fridge freezer off because low voltage has been detected.

• Check with a different power source, for example a different vehicle or 240V AC power. If changing the power source fixes the issue, the possible cause could be the original power source.
• Check that the correct battery protection setting has been selected to suit the customer’s requirements.
• Check the vehicle wiring is adequate.
  • For cable lengths up to 6m (20’), ARB recommends a minimum automotive cable size of 6 mm (4.5 mm2).
  • For cable lengths greater than 6m (20’), ARB recommends that you consult a qualified technician for advice on the correct wire size.
• Check that all terminals and joints are clean and in good condition.
• Check that the battery voltage at the socket is above the set cut-out voltage (refer to section 6.6 of the Service Manual). To ensure that voltage drop is accounted for when measuring this voltage, refer to section

NOTE: The battery protecting system only controls 12 and 24V DC supplies. To confirm that the fridge freezer is operating correctly, connect the fridge freezer to a standard 100-240V AC supply.

Display “E2” and Check light flashes 2 times every 4 seconds – Fan issue:

The control system has turned the fridge freezer off because the fan is drawing more than 0.6 amp while the compressor is running. This could be because the fan is running slowly or not running at all.

• Check that the fan is not obstructed or dirty.

Display “E3” and Check light flashes 3 times every 4 seconds – Compressor start issue:

The compressor will not start because the refrigerant system has become unbalanced. This can occur when the power to the fridge freezer is briefly interrupted.

• Turn the fridge freezer off and disconnect it from its power supply.
• Allow the fridge freezer to stand for 10 to 15 minutes to allow the system to equalize.
• Reconnect the fridge freezer to the power supply and turn it on.
• Compressor control box fault.

Compressor fault. Display “E4” and Check light flashes 4 times every 4 seconds – Low motor speed: The compressor motor is running below its minimum maintainable speed. This could be because the refrigerant system has been overcharged.

Consult a refrigeration mechanic to check that the system is charged with the correct amount of refrigerant.

• Move the unit to a lower ambient temperature.
• Clean vents and ensure clean air flows over the compressor.
• Fan fault.

Display “E5” and Check light flashes 5 times every 4 seconds – Over temperature:

The fridge freezer has stopped operating because the control unit has become too hot.

• Check to ensure that there is adequate ventilation around the control unit and the compressor. 
• Check that the fan is operating correctly. The fan must always be running when the compressor is running.
• The fridge freezer may be operating in extremely high ambient temperatures. For example in a sealed stationary vehicle that is parked in the direct sunlight. Try to improve the ventilation around the fridge freezer or shield it from direct sunlight.
• Fan fault.