Invalid Data Received From Body Control Module
What does U0406 mean?
The U0406 code means the vehicle's onboard diagnostic system has detected: Invalid Data Received From Body Control Module. This is a moderate severity code.
Common Symptoms
- Exterior lights behaving erratically
- Power accessories intermittently failing
- Remote keyless entry inconsistent
- Interior lights turning on or off randomly
- Multiple body system warning messages
Probable Causes (Ranked by Likelihood)
- Failing BCM sending corrupted data Very High
- BCM power or ground connection degraded High
- Water intrusion into BCM housing Moderate
- CAN bus interference from aftermarket accessories Moderate
Step-by-Step Diagnostic Procedure
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Check BCM power and ground connections for voltage drop
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Inspect BCM housing for signs of water intrusion
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Remove any aftermarket accessories connected to vehicle wiring
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Monitor BCM live data for erratic or impossible values
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Check CAN bus signal quality at the BCM connector
Frequently Asked Questions
Can I drive with code U0406?
Generally yes, but watch for unpredictable lighting or accessory behavior. If headlights or turn signals are affected, drive only during daylight until repaired.
What causes U0406?
Usually a failing BCM or degraded power and ground connections. FCA/Stellantis vehicles are known for BCM issues related to water intrusion.
Is U0406 expensive to fix?
Expect $150 to $800. Check power and ground connections first. BCM replacement with programming is the most expensive repair option.