U0409
Invalid Data Received from Vehicle Security Control Module
The vehicle security / alarm controller is sending implausible status data (e.g. armed/unarmed jitter). Alarm and immobilizer behaviour can become unpredictable.
The vehicle security / alarm controller is sending implausible status data (e.g. armed/unarmed jitter). Alarm and immobilizer behaviour can become unpredictable.
Common causes
- medium
Security module internally failed
A plausible cause — test and verify before replacing parts.
Typical part cost: $130-880
- low
Gateway module routing CAN messages incorrectly
Less common, but worth ruling out after the more likely causes.
Typical part cost: $130-880
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does U0409 mean?
U0409 means "Invalid Data Received from Vehicle Security Control Module". It is a generic OBD-II code that points to a fault in the network / communication.
What are the most common causes of U0409?
security module internally failed; gateway module routing can messages incorrectly; can terminating resistor (120 ω) drifted out of spec — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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