Pulse-width encoding
Each data nibble is represented by the time between falling edges, allowing multiple values in one frame.
SENT / Communication network
SENT SENSOR PROTOCOL
High-resolution one-wire sensor data
NETWORK GUIDE11/14
TOPOLOGYPoint-to-point sensor-to-controller connection
PHYSICALSingle signal wire with power and sensor ground
DATA RATENibble timing defined by the sensor tick period
Correct theory and operation
HOW SENT
COMMUNICATES.
Understand the normal architecture, signaling and message rules before deciding that a voltage or waveform is incorrect.
Status and CRC
Frames include status information and a checksum so the controller can detect corruption.
Common mistakes
AVOID THE
FALSE CLUE.
- Testing with the connector unplugged when the fault only appears under load.
- Using a generic voltage value instead of the vehicle-specific specification.
- Skipping power, ground and reference checks before condemning the component.
- Moving the harness or clearing codes before capturing the original evidence.
- Replacing a part without repeating the test.
Reading the signal
Good waveform / normal communication
The synchronization/calibration pulse and subsequent pulse intervals decode into valid data and status with the expected checksum. Measurement information is carried by timing, not by pulse height.
Faulty waveform / fault indications
Timing outside the protocol tolerance, missing edges, checksum errors or invalid status can indicate signal or sensor trouble. A square-looking trace can still encode a fault; check decoded values against the actual measured condition.
COMPLETE TEST SEQUENCE
- Identify the signal, supply and ground.
- Measure supply under load.
- Scope several complete frames.
- Decode nibble timing and verify checksum behavior.
Confirm the network, topology, awake state and test conditions from vehicle-specific information.