Ignition Key Transmitter 1 Signal Invalid
The vehicle's computer has detected an invalid signal from the ignition key transmitter.
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)
Your car is trying to read the signal from the key fob or key, but it’s getting gibberish instead. This can happen if the key is dead or there's a problem in the communication.
What the computer is actually seeing
The ignition control module expects a certain digital signature from the key transmitter when the key is in the ignition. If the signal is missing or incorrect, it triggers this code.
What a healthy reading looks like
The key transmitter should send a unique digital code at around 1 to 3 volts; anything outside this range is deemed invalid.
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 battery in the key fob; replace if low or dead.
- 2Inspect the key fob for physical damage or wear.
- 3Clear the code and attempt to start the vehicle; if it returns, check for wiring issues.
- 4Examine wiring and connections from the key fob to the ignition module for corrosion or damage.
- 5If the problem persists, test a spare key or key fob if available.
Common causes
- Dead key fob battery
- Faulty key fob
- Wi-Fi or RF interference
- Faulty ignition control module
- Corroded wiring or poor connections
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
You can drive the vehicle if it starts, but if it does not recognize the key, you could get stranded.
Will this code come back after clearing it?
Yes, if the underlying issue isn't fixed, the code will return.
Why does this code pair with a specific key fob?
Each key fob has a unique signal; issues with one fob can trigger this error without affecting another.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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