OBD-II trouble code
U0126: Lost Communication with Steering Angle Sensor Module
A module on the network can no longer hear from the steering angle sensor. Stability control and related systems usually disable themselves and warning lights come on. Usually a power, ground, wiring, or connector fault at the sensor.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $700
- DIY difficulty
- Shop recommended
What does U0126 mean?
U0126 is set when another module on the vehicle's communication network — most often the ABS/stability control module — stops receiving messages from the steering angle sensor (SAS). The steering angle sensor sits in the steering column and reports how far and how fast the driver is turning the wheel. Electronic stability control compares that steering input against what the vehicle is actually doing (yaw, lateral acceleration, and wheel speeds) to decide whether the car is understeering or oversteering and whether to intervene with brakes or throttle. When the network loses contact with the steering angle sensor, the controller no longer knows where the wheel is pointed, so it logs U0126 and shuts down the features that depend on that data.
The causes follow the usual communication-code pattern. The sensor may have lost power or ground through a blown fuse, a corroded ground, or a wiring fault in the column. The CAN or LIN wiring to the sensor may be damaged, and its connector may be corroded or have a backed-out terminal — faults that often appear after airbag, clockspring, steering column, or multifunction switch service that disturbs the harness behind the wheel. The sensor itself can fail internally, or another module on the bus can disrupt communication for everyone. On many vehicles the steering angle sensor must be calibrated after any steering, alignment, or suspension work; an uncalibrated or out-of-range sensor can also trigger faults.
The symptoms are usually clear on the dash: the stability control (ESC/ESP), traction control, and ABS warning lights typically illuminate, sometimes alongside a power steering warning, because those systems disable themselves when they lose the steering reference. The car generally still drives and steers normally — power steering and base brakes are unaffected — but the safety nets that catch a skid are off. Because stability control is a genuine safety feature, U0126 should be diagnosed promptly even though the vehicle remains driveable.
Common causes
- Blown fuse feeding the steering angle sensor
- Corroded or loose ground in the steering column circuit
- Damaged CAN or LIN wiring to the steering angle sensor
- Corroded or backed-out terminal at the sensor connector
- Harness disturbed during airbag, clockspring, or column service
- Failed steering angle sensor
- Sensor not calibrated after steering, alignment, or suspension work
- Another module on the bus disrupting network communication
Symptoms
- Stability control (ESC/ESP) and traction control warning lights on
- ABS warning light on
- Possible power steering warning light
- Stability and traction control disabled
- Steering and base braking still function normally
- Scan tool can't communicate with the steering angle sensor
- Steering angle reads a default or implausible value
Diagnostic steps
- 1.Scan all modules and confirm the steering angle sensor is the unreachable one while others respond.
- 2.Check the fuse and power feed for the steering angle sensor circuit.
- 3.Inspect the sensor connector and column ground for corrosion, looseness, and backed-out terminals.
- 4.Review any recent airbag, clockspring, column, or multifunction-switch work that could have disturbed the harness.
- 5.Measure the communication and reference circuits at the sensor connector and verify continuity back to the bus.
- 6.If wiring, power, and ground are good but the sensor still won't communicate, replace the sensor; then perform the required steering angle calibration with a scan tool.
Repair cost
$100 – $700
A blown fuse, corroded ground, or connector repair is the cheapest fix at $100-$300 plus $150-$300 diagnostic time. Wiring repair runs $200-$500. Steering angle sensor replacement typically runs $250-$700 including the required calibration; on some vehicles the sensor is integrated with the clockspring, which raises parts cost. Calibration must be performed with a scan tool after replacement or alignment.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with module communication / can bus diagnosis preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.