P0EC5: A/C Compressor Motor Speed Sensor Circuit Range/Performance

What it means

The A/C compressor motor speed sensor signal is outside the expected range or does not track compressor speed plausibly. The module sets this code when the signal fails its range or performance checks.

How it works

The A/C compressor motor speed sensor reports how fast the compressor motor is turning, allowing the control module to check that commanded and actual operation agree. This code sets when the speed signal is outside its expected range or does not track compressor operation plausibly.

Common causes

Most likely first.

1. Faulty speed sensor
2. Compressor motor or inverter fault
3. Damaged sensor wiring
4. Loose or corroded connector

Symptoms

• A/C may not cool or heat properly
• A/C warning light
• Hybrid or EV warning light

How to diagnose it

1. Record freeze-frame data and compare live compressor speed with the commanded speed and A/C operating state.
2. Inspect the compressor speed sensor connector and harness for looseness, corrosion, chafing, or other damage.
3. Check the speed sensor circuit for opens, shorts, and poor connections using the manufacturer's wiring information.
4. Compare the sensor signal and compressor response with the manufacturer's specification while the system is operated as specified.
5. If the sensor circuit passes, have the compressor motor and inverter checked for a speed-tracking fault.

Common fixes

• Secure a loose speed sensor connector or repair poor terminal contact.
• Repair damaged compressor speed sensor wiring.
• Replace the speed sensor if it fails testing.
• Repair the compressor motor or inverter only if tests identify it as the cause.

Can I keep driving?

The A/C or heat pump may stop operating, and a hybrid or EV warning may appear. Driving may be possible, but follow the vehicle's warning messages and ensure you can keep the windscreen clear.