P0EC5: Air Conditioning Compressor Motor Speed Sensor Range/Performance
What to do
The air conditioning will be weak or absent, and heating too on a heat-pump car. Ask for the refrigerant charge to be checked first — a compressor running fast in an empty system is destroying itself, and fitting a new one without finding the leak destroys that one as well.
What this code means
The compressor motor's speed does not match what was commanded.
An electric compressor's speed is its output. A belt-driven one turns at whatever the engine is doing and is regulated by varying its displacement or by clutching it on and off. An electric one is simply told how fast to run, which is why an electric car's air conditioning can hold a steady cabin temperature instead of cycling.
So a speed that does not follow the command is the compressor failing to do the one thing asked of it, and the useful question is which direction.
Slower than commanded means load — the compressor is working against more resistance than it should. That is a system pressure problem: an overcharge, a blockage, a condenser that cannot reject heat, or a compressor beginning to seize. The current codes at P0EAD would usually be stored alongside, because a motor fighting a load draws more current.
Faster than commanded means the opposite — there is nothing to compress, which points at a refrigerant charge that has largely escaped. And that is the dangerous one for the part, because the oil that lubricates the compressor travels in the refrigerant: a compressor spinning freely in an empty system is destroying itself, and the argument is at P0D6F.
Have the charge checked before anything is replaced. A new compressor in an empty system fails the same way.
Likely causes
Start here
- Low refrigerant charge · moderate
- Faulty electric air conditioning compressor · specialist
- Corroded or loose connector · specialist
Less common
- Faulty air conditioning refrigerant pressure sensor · specialist
Rare
- Incorrect compressor oil in a high voltage system · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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