U0126
System
Network (CAN Bus)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Lost Communication with Steering Angle Sensor Module

Understand U0126, common causes, and the right TOPDON scanner to diagnose it.

Steering angle sensor module offline — ESC and EPS may be disabled until calibrated.

Common symptoms

  • ESC light on
  • Heavy steering feel (EPS)
  • Stability control disabled

Typical causes

  • Clock spring failure
  • SAS module fault
  • Battery disconnect without recalibration

What scanner do you need?

Full-system scanner (engine, ABS, SRS, transmission, service resets)

Use live data and freeze frame to confirm the fault before replacing parts. ABS, SRS, and network U-codes usually require a full-system scanner.

Diagnostic tips

  • Record freeze frame data when the code first sets
  • Clear the code only after fixing the root cause
  • Check for related pending codes that point to a common issue
  • Verify battery voltage is above 12.4V before chasing sensor codes

Recommended TOPDON scanners

Frequently asked questions

Can I diagnose U0126 with a basic code reader?
U0126 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with U0126?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.