IGNITION KEY CODE ERROR
The vehicle's ignition key or fob is not recognized by the 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)
When you try to start the car, the computer checks if the key has the right code. If it doesn’t match, the system thinks the key is wrong, and won't allow the car to start or may disable certain systems.
What the computer is actually seeing
The BCM (Body Control Module) expects a specific key code signal from the ignition key/fob. If it receives a different code or no signal, it throws the B1601 code.
What a healthy reading looks like
Key code from the ignition switch should match the stored key code in the BCM. Typical voltage for a recognized key signal ranges from 0.5V to 5V.
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.
- 11. Inspect the ignition key/fob for physical damage or wear. If damaged, replace.
- 22. Check the battery in the key fob. Replace if voltage is less than 3V.
- 33. Verify wiring and connectors between the key reader and the BCM for any corrosion or loose connections.
- 44. Use a scan tool to check if other key-related codes are present.
- 55. If all checks are okay, attempt to reprogram the key using the manufacturer's procedure. If reprogramming fails, replace the BCM.
Common causes
- Faulty ignition key or fob
- Bad BCM (Body Control Module)
- Poor connection or corrosion in the ignition system
- Dead battery in the key fob
- Misalignment of the key reader unit
Typical repair cost
$$ - $$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It’s best not to drive, as the vehicle may not start or could disable key systems.
Will this code come back after clearing?
If the underlying issue isn't fixed, the code is likely to return.
Why does this code appear with other codes?
B1601 often pairs with other key-related codes indicating a broader issue with the key or BCM.
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