OBD-II Fault Code

U2004: Audio Steering Wheel Control Unit is Not Responding

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for U2004.

System family

Network

Generic/SAE

Repair category

Steering system

Use this category to narrow your checks before replacing parts.

Severity

High

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What U2004 usually means

Audio Steering Wheel Control Unit is Not Responding.

Common symptoms

Multiple warning lights or modules not communicating; Steering warning lamp or heavy/abnormal steering

Likely causes

Low voltage; Steering angle/torque sensor fault; Power steering motor/module issue; Wiring fault

Diagnostic checks

Check battery condition, module fuses, grounds and network connectors before replacing modules; Check battery/charging system; Calibrate steering angle sensor if required after repair/alignment

Repair guidance

Repair wiring/power supply, perform calibration, replace failed sensor/module after confirmation

Verification after repair

Rescan all modules and confirm communication returns

Note: Confirm vehicle make/model/year because manufacturer-specific codes can vary. A DTC identifies a circuit or system condition, not always the failed part.