Vehicle Security System Fault
Indicates a fault in the vehicle's security system.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The vehicle's computer detects a problem with the security system, which could prevent the engine from starting or lock out the key fob.
What the computer is actually seeing
The Body Control Module (BCM) monitors the signals from the key fob and all related security components. If it notices that the signal is missing, weak, or wrong, it sets this code.
What a healthy reading looks like
BCM should receive a strong, consistent signal from the key fob, typically around 12V when the button is pressed.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check the key fob battery; replace if low or dead. Verify key fob functions properly by testing with another vehicle if possible.
- 2Inspect the wiring and connectors to the BCM and the key fob receiver for damage or corrosion.
- 3Use a scan tool to check for other related codes that may indicate further issues, such as B1690 for low signal strength.
- 4If everything seems normal but the code persists, suspect a faulty BCM and test or replace it as needed.
Common causes
- Faulty key fob
- Dead key fob battery
- Damaged wiring or connectors
- Faulty Body Control Module (BCM)
- Interference from aftermarket devices
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive if the security system is malfunctioning, as it may prevent your vehicle from starting.
Will the problem come back after resetting?
If the root cause isn't fixed, the code will likely return after clearing it.
Why does this code pair with other codes?
Security codes often trigger together if they're related to the same system, indicating that multiple components may be affected.
Working a real vehicle right now?
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