P0EC2: A/C Refrigerant Temperature Sensor B Circuit High

With P0EC2 the signal of refrigerant temperature sensor B is stuck near the reference voltage. An NTC thermistor would only get there at extreme cold, so an open circuit somewhere in the loop is far more likely. No manufacturer documents P0EC2 publicly. Mitsubishi's procedure for the analogous evaporator outlet sensor of the Outlander PHEV shows the logic: the A/C amplifier sets its open-circuit code after 4 seconds of high input while READY is on or the battery is charging, and the technician measures about 5 V at the unplugged connector and checks both lines for continuity under 2 ohms. A false cold reading may lock out heating or cooling. Low counterpart: P0EC3.

Low severity. Can I keep driving?Yes, you can keep driving. The air conditioning may not work.

Symptoms

Very low refrigerant temperature shown for sensor B
Heating via heat pump or cooling unavailable

Most likely causes

Open signal or ground line between sensor B and module
Connector not fully seated after A/C work
Sensor B open internally

What to check, in order

Start with the simplest. You can tick off each step.

Check the sensor pressure in live data
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Check the relay and connector
Have the refrigerant charge and any leaks checked at a repair shop authorized to handle refrigerant

Good to know

Repair difficulty: medium

What each character of P0EC2 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
E: Subsystem depends on the code range
C2: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0EC2?

Yes, you can keep driving. The air conditioning may not work.

What causes code P0EC2?

The most common causes are: open signal or ground line between sensor B and module; connector not fully seated after A/C work; sensor B open internally.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.