What Does B2404 Mean?
This code indicates the Body Control Module (BCM) has detected an electrical fault in the audio steering wheel control switch circuit. The fault may be an open circuit, short to ground, short to power, or high resistance in the wiring or switch assembly that connects the steering wheel-mounted audio controls to the BCM or audio head unit. This prevents proper communication between the steering wheel buttons and the audio system.
Common Causes
35%
Damaged or worn steering wheel control switch assembly with internal contact failure
30%
Broken or corroded wiring in the clockspring assembly behind the steering wheel
20%
Loose, corroded, or damaged electrical connector at steering wheel control module or BCM
10%
Faulty BCM or audio head unit with internal circuit board failure
5%
Damaged wiring harness between steering column and BCM due to chafing or pinch points
Diagnostic Steps
1
Step 1: Perform visual inspection of steering wheel control switches for physical damage, missing buttons, or liquid intrusion. Test each audio control button function and note which buttons are non-responsive.
2
Step 2: Remove steering wheel airbag module (following proper safety procedures) and inspect clockspring connector and wiring for damage, corrosion, or loose connections. Check for continuity through the clockspring with steering wheel centered and turned full left/right.
3
Step 3: Using a digital multimeter, backprobe the steering wheel control circuit wires at the BCM connector and measure resistance values while pressing each button. Compare readings to manufacturer specifications (typically 150-2500 ohms depending on button pressed).
4
Step 4: Check for power and ground at the steering wheel control module connector with ignition on. Verify reference voltage (typically 5V or 12V) is present on the supply wire using a multimeter.
5
Step 5: If all voltage and resistance readings are correct at the BCM connector, use scan tool to monitor steering wheel control button input data PIDs in live data while pressing buttons to verify BCM is receiving signals.
6
Step 6: Clear codes, reconnect all components, and perform functional test of all steering wheel audio controls. Road test vehicle and verify no code returns and all functions operate normally.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an electrical fault in the audio steering wheel control switch circuit. The fault may be an open circuit, short to ground, short to power, or high resistance in the wiring or switch assembly that connects the steering wheel-mounted audio...
The most common cause of B2404 (Audio Steering Wheel Switch Circuit Fault) is: Damaged or worn steering wheel control switch assembly with internal contact failure
Typical repair costs for B2404 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is safe to drive as it only affects convenience features for audio control. The primary audio system controls on the head unit remain functional. Repair can be scheduled at convenience with no urgency.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2404 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Audio System
Difficulty
Type
Generic (SAE)
Recommended Tools
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