Ako E162

What does Ako E162 mean?

On AKO-16524A/16525A advanced cold room controllers, E162 is a combined reference to probe fault alarms for Probe 1, 2, or 3. The specific probe in fault is indicated by the accompanying E1, E2, or E3 designation. The fault is an open circuit, a crossed circuit, or a temperature reading outside the valid probe range. Alarm relay and audible alarm are activated.

Symptoms

• E1, E2, or E3 appears on the display alongside the E162 alarm group.
• Alarm relay and audible alarm activate.
• Temperature regulation affected depending on which probe has faulted.
• Fans may run continuously if the evaporator probe (E2) is involved.
• Defrost end-by-temperature is disabled for the faulted probe.

Common causes

• Open circuit in a probe cable — the most common cause across all three probes.
• Short circuit or crossed wiring at a probe terminal block.
• Moisture ingress on the probe causing a resistance shift outside valid limits.
• Probe temperature reading exceeds sensor limits for the installed probe type.
• Probe type mismatch between the installed sensor and controller parameter settings.

Diagnostic steps

1. 01

   Identify which probe has faulted (E1, E2, or E3)

   The display will show E1, E2, or E3 alongside or alternating with the temperature. Identify the probe number before starting inspection to target the correct sensor and cable.

2. 02

   Inspect the probe cable and connector

   Power off the controller and inspect the full cable run for the identified probe. Look for cuts, pinching, or corrosion at the probe tip and cable ends.

3. 03

   Check terminal block connections

   Verify the probe is firmly seated at the controller terminal block. Re-seat loose connections and clean any corroded contacts.

4. 04

   Measure probe resistance

   Disconnect the probe and measure resistance at the tip with a multimeter. Compare against the AKO NTC/PTC resistance–temperature chart. Open circuit or out-of-range resistance confirms probe failure.

5. 05

   Replace the faulted probe

   Install an AKO-approved replacement probe. Route the cable separately from power wiring. Restore power and confirm the E1/E2/E3 fault clears and normal regulation resumes.

When to call a professional

Call a licensed refrigeration technician if probe replacement does not clear the fault, if multiple probes have faulted simultaneously suggesting a controller board issue, or if product temperatures have risen significantly during the fault period and food safety compliance needs to be assessed and documented.