How to determine if a Hall Effect Sensor is working properly?
Feb 02, 2026| I. General Testing Steps
1. Power Supply Check
Use a multimeter to measure the power supply line voltage (e.g., the red and black wires of the Hall effect sensor wiring in an electric vehicle). It should normally be 5V or 12V. If there is no voltage, it may indicate a wiring or ECU fault.
2. Signal Output Test
Keep the black probe grounded. Use the red probe to test the signal lines sequentially (e.g., yellow/green/blue wires) while simultaneously triggering the magnetic field (e.g., rotating a motor or bringing it close to a magnet).
Linear type: The output voltage should gradually change with the magnetic field strength.
Switch type: The output is low when the magnet is near and high when it is far away.
Bipolar latching type: The output is at a fixed level when the magnet is near and remains unchanged after it is removed; conversely, the output is opposite when the magnet is near.
3. Resistance Test
Measure the resistance between the sensor and the ECU terminals. It should be ≤1.5Ω. If the resistance is too high, it may indicate poor wiring contact.
II. Scenario-Specific Testing Methods
1. Electric Vehicle Motor Hall Sensor
Locate the five Hall sensor wires on the controller (red/black power wire, yellow/green/blue signal wire).
After powering on, measure the power line voltage to approximately 5V.
When rotating the motor, the signal line voltage should jump from 0V to 5V.
2. Electric Vehicle Throttle Hall Sensor
Connect the red probe to the green wire and the black probe to the black wire. When rotating the throttle, the voltage should rise from 1V to 3.5V.
3. Hall Current Sensor
Disconnect the ignition switch and measure the voltage at the power terminal; it should match the specifications.
Measure the resistance between the sensor and the ECU terminals; it should be ≤1.5Ω.
III. Auxiliary Tools
Multimeter: Suitable for basic voltage and resistance testing.
Repair Tool: Self-powered; simply plug in the connector and rotate the throttle or motor for quick assessment.
Oscilloscope: Observe whether the signal waveform is a rectangular pulse (high level 5V, low level 0.3V).
IV. Fault Symptoms
Failure to start: A faulty motor Hall sensor may prevent commutation.
Abnormal noise: A damaged throttle Hall sensor may cause the throttle to jam.
Abnormal signal: Output voltage does not change abruptly or the waveform is distorted.
