Why is my airbag light on with a steering angle sensor fault?

Because on a great many cars they are the same part. The clock spring is a coiled ribbon cable behind the steering wheel that keeps the wheel's circuits connected as it rotates, and manufacturers frequently build the steering angle sensor into the same assembly. When that assembly fails, the airbag deployment circuit and the angle sensor go together, so you get an SRS code and a steering angle code from one component. A horn that has also stopped working is the third clue, since the clock spring carries that too.

Does the steering angle sensor need calibrating?

Yes, and it is one of the most commonly skipped steps in a repair. The sensor reports an angle relative to a stored straight-ahead reference, and that reference has to be set. It is lost or invalidated by wheel alignment, steering rack or column work, some suspension jobs and, on certain cars, a battery disconnection. Most cars need a short scan tool procedure to reset it; a few learn it by being driven straight for a short distance. Without it the modules reject the reading and the lamps stay on.

Will U0126 fail an MOT?

Yes, and quite possibly more than once. A stability control lamp indicating a malfunction is a major defect with 35,322 recorded failures. If the fault involves a shared clock spring assembly, the airbag lamp will be lit too, and that is a separate major defect with 84,147 recorded failures. Where the power steering lamp is also on, that adds a third, recorded 205 times in the DVSA data behind this site.

Can I still steer normally with this fault?

Yes. The steering wheel is connected to the road wheels mechanically through the column and the rack, and none of that depends on the angle sensor. The sensor only reports where the wheel is so that other systems can use the information. What you lose is stability control, which cannot compare your intended direction with the car's actual behaviour, and possibly some of the finesse in the power steering assistance. The car remains fully controllable.

Network code · standard

U0126No communication with the steering angle sensor

Standard definition: Lost Communication with Steering Angle Sensor Module

Last updated 27 July 2026

Quick answer

The car has lost the message that tells it where the steering wheel is pointing. Stability control cannot work without knowing where you are steering, so it shuts down, and power steering assistance can be affected too.

How the car works this out

The steering angle sensor sits at the base of the steering column and reports the wheel's position and the speed it is being turned, broadcasting that over the network several times a second. Stability control, lane keeping, adaptive lighting and the power steering module all consume it. U0126 is stored when those messages stop arriving. There is a detail specific to this sensor that explains a lot of the faults: on very many cars it is combined into the same assembly as the clock spring behind the steering wheel, so a single failed part can produce both a steering angle code and an airbag code.

What you might notice

Stability control and traction control lamps on
Power steering lamp on as well on some cars
Airbag lamp on too, where the sensor shares an assembly with the clock spring
Lane keeping assist and adaptive cruise unavailable
Adaptive headlights not turning into corners
Steering assistance feeling uneven or not self-centring properly

What causes it

Most likely first. A code names the check that failed, not the part that failed it, so more than one of these can produce the same number.

1A failed steering angle sensor, often as part of a failed clock spring assemblyCommon
How to check: Check whether the airbag lamp and the horn are affected too. A dead horn alongside these codes points at the combined assembly rather than a standalone sensor.
2A connector at the base of the steering column disturbed or corroded, commonly after column, airbag or dashboard workCommon
3A calibration lost after alignment, steering, suspension or battery workCommon
How to check: Ask whether the sensor has been recalibrated since the last work. It is a short scan tool procedure on most cars and costs a fraction of a part.
4Damaged network wiring in the column loom, which moves with the adjustable columnPossible
5Low system voltage dropping the module off the networkPossible
6A wider network fault where this sensor is one of several missingLess common

What to do about it

1Check whether the airbag lamp is also on and whether the horn works. That combination usually identifies a clock spring assembly and saves a great deal of guesswork.
2Ask about calibration first if there has been any recent alignment, steering, suspension or battery work.
3Have the connector at the base of the column inspected, particularly if anything has recently been worked on in the dashboard.
4Disconnect the battery and observe the manufacturer's waiting period before any work around the steering wheel, since the airbag and its clock spring are in the same place.
5Expect a calibration procedure after the repair. A new sensor does not know where straight ahead is until it is told.

Can you keep driving?

Briefly, gently

The steering itself is entirely mechanical and unaffected — the car goes exactly where you point it. What you lose is stability control, which cannot decide whether the car is going where you intended without knowing where you are steering, and possibly some power steering refinement. If the airbag lamp has come on with it, the restraint system is likely out of service too, which raises the urgency considerably.

Will it fail an MOT?

A stability control lamp indicating a malfunction is a major defect with 35,322 recorded failures in the DVSA data behind this site. Where the sensor shares an assembly with the clock spring, the airbag lamp usually comes on as well, and that is a separate major defect with 84,147 recorded failures. If the power steering lamp is lit too, that is a third, recorded 205 times. The tester also assesses steering play and the condition of the steering components directly, which is a separate inspection from any of the lamps.

The light this turns on

Stability control warning lightElectronic stability control has found a fault and switched itself off. The car drives normally in a straight line, but the system that detects a skid starting and brakes individual wheels to correct it is no longer available.

Common questions

Why is my airbag light on with a steering angle sensor fault?: Because on a great many cars they are the same part. The clock spring is a coiled ribbon cable behind the steering wheel that keeps the wheel's circuits connected as it rotates, and manufacturers frequently build the steering angle sensor into the same assembly. When that assembly fails, the airbag deployment circuit and the angle sensor go together, so you get an SRS code and a steering angle code from one component. A horn that has also stopped working is the third clue, since the clock spring carries that too.
Does the steering angle sensor need calibrating?: Yes, and it is one of the most commonly skipped steps in a repair. The sensor reports an angle relative to a stored straight-ahead reference, and that reference has to be set. It is lost or invalidated by wheel alignment, steering rack or column work, some suspension jobs and, on certain cars, a battery disconnection. Most cars need a short scan tool procedure to reset it; a few learn it by being driven straight for a short distance. Without it the modules reject the reading and the lamps stay on.
Will U0126 fail an MOT?: Yes, and quite possibly more than once. A stability control lamp indicating a malfunction is a major defect with 35,322 recorded failures. If the fault involves a shared clock spring assembly, the airbag lamp will be lit too, and that is a separate major defect with 84,147 recorded failures. Where the power steering lamp is also on, that adds a third, recorded 205 times in the DVSA data behind this site.
Can I still steer normally with this fault?: Yes. The steering wheel is connected to the road wheels mechanically through the column and the rack, and none of that depends on the angle sensor. The sensor only reports where the wheel is so that other systems can use the information. What you lose is stability control, which cannot compare your intended direction with the car's actual behaviour, and possibly some of the finesse in the power steering assistance. The car remains fully controllable.

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