U2104

Code

Generic U — Network/User

Invalid Data Received From Steering Angle Sensor

Brand: Generic

Type: U — Network/User

Views: UK: 20 EN: 27 RU: 24

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty steering angle sensor
Corroded, loose or damaged connector/wiring
Poor sensor ground or supply voltage
CAN/LIN bus communication error or short
Module software/coding mismatch or firmware bug
Sensor not calibrated or calibration lost after service

Symptoms

Steering-related warning lamp(s) (EPS, VDC/ESC, ABS)
Steering angle readout incorrect, inconsistent, or not updating on scan tool
Loss or reduction of electronic steering assist or stability control functions
Lane-keeping, adaptive cruise or other driver assists disabled
Intermittent faults that appear under steering movement or vibration

What to check

Read U2104 and any related codes (U0xxx, U01xx, B1xxx, C1xxx) with a capable scan tool and note freeze frame/livedata
Confirm vehicle battery voltage is within spec during testing
Verify steering angle sensor live data vs actual steering wheel rotation (steering wheel turns vs reported degrees)
Inspect connector(s) at steering angle sensor and ECU(s) for corrosion, bent pins, water intrusion, or damage
Check continuity/resistance of power, ground, and signal/CAN wires back to the module (while powered off when required)
Observe CAN bus health: error counters, bus voltage levels, and other nodes reporting similar faults

Signal parameters

Typical steering angle range: ±360° to ±720° (vehicle dependent) reported in degrees
Analog sensor: 0.5–4.5 V signal range per channel or dual redundant channels
Digital: CAN message carrying steering angle (example IDs vary by manufacturer); message refresh rate commonly 10–100 Hz
Expected update rate: steady periodic updates; long gaps or duplicated IDs indicate bus issues
Checksum or CRC present in many manufacturer CAN messages — invalid CRC often flagged as bad data
Supply voltage near battery voltage (nominal 12 V) and ground resistance low (

Diagnostic algorithm

Safety: Park vehicle, chock wheels, disable airbags if working near steering column per manufacturer procedures.
Scan: Connect a dealer-level or advanced scan tool. Record U2104 plus any related codes and freeze frame data. Check live steering angle, yaw/rate sensors and wheel speeds.
Reproduce: With the tool watching live data, slowly rotate steering wheel and observe steering angle output for stalls, dropouts, jumps or incorrect scaling.
Visual: Inspect steering column harness, connector boots, and routing for chafing, pin corrosion, or water ingress. Wiggle harness while observing live data to find intermittent faults.
Power/Ground: Measure sensor supply voltage and ground integrity with key on. Repair any low supply or poor ground before proceeding.
Bus/Comm: Check CAN/LIN bus voltage levels, termination and error counters. Isolate the sensor network and check other nodes for communication errors.
Wiring: If suspect, perform continuity and short tests between the sensor and controlling module pins (with battery disconnected when required).
Software/Calibration: Confirm correct module coding and software level. Perform steering angle sensor relearn/calibration per service procedure after repairs or replacement.
Repair/Replace: If wiring and power/ground are good and data remains invalid, replace the steering angle sensor. After replacement, perform required relearn/calibration.
Verify: Clear codes, perform a test drive and re-scan. Confirm U2104 does not return and that live steering angle matches physical steering input across full range.

Likely causes

Open/short in sensor power, ground, or signal wires
CAN transceiver fault or low bus voltage (dominant/recessive errors)
Steering angle sensor internal fault (faulty Hall/MEMS or potentiometer)
Incorrect module programming or missing steering angle calibration
Connector corrosion at the steering column or behind dash

Fault status

⚠️ Status

Invalid data received from steering angle sensor — communication/data integrity fault detected. Check wiring, power/ground, CAN bus and sensor calibration.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours