What it means
The circuit for A/C compressor motor voltage sensor B has a detected fault. The module sets this code when the sensor circuit fails its electrical monitoring checks.
How it works
The A/C compressor motor voltage sensor B circuit provides the module with a voltage measurement used to monitor the electric compressor drive. This code sets when that sensor circuit fails its electrical checks, so the module may disable or limit compressor operation to protect the system.
Common causes
Most likely first.
- Failed voltage sensor
- Open or shorted wiring
- Loose or corroded connector
- A/C compressor inverter fault
Symptoms
- A/C may not cool or heat properly
- A/C warning light
- Hybrid or EV warning light
How to diagnose it
- Record freeze-frame data and check for related A/C compressor or hybrid-system codes before clearing anything.
- Check live data for the A/C compressor motor voltage sensor B reading and note whether it is absent or implausible when A/C is requested.
- With the vehicle powered down according to the manufacturer’s high-voltage safety procedure, inspect the sensor B wiring and connector for damage, looseness, or corrosion.
- Check the sensor circuit for opens and shorts and verify connector and supply conditions using the manufacturer’s procedure; avoid probing high-voltage compressor wiring unless qualified and equipped.
- If the circuit checks out, test the voltage sensor B and compressor inverter as directed by the manufacturer to identify which component has failed.
Common fixes
- Secure or clean a loose or corroded sensor B connector.
- Repair open, shorted, or damaged wiring in the voltage sensor B circuit.
- Replace the voltage sensor if it fails the manufacturer’s checks and the circuit is sound.
- Repair the A/C compressor inverter if testing confirms it is the source of the circuit fault.
Can I keep driving?
You can generally drive if the vehicle has no other warnings or power problems, but the A/C may not cool or heat as expected. Stop if a hybrid-system warning is accompanied by reduced power, and avoid attempting repairs on high-voltage compressor wiring.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.