Body Control Module (BCM) Ignition Input Circuit Failure
The BCM is not receiving a proper ignition signal from the ignition switch.
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 Body Control Module (BCM) needs to know when the ignition is on. If it doesn't get that signal (like a bad wire or switch), it thinks the car is off and won't allow some systems to work, causing potential safety issues.
What the computer is actually seeing
The BCM expects a voltage signal between 10-14 volts when the ignition is on. If it sees a steady voltage below 10 volts or an intermittent signal, it will trigger this code.
What a healthy reading looks like
BCM should read 12-14 volts with ignition on; 0 volts with ignition off.
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. Check ignition switch operation: with the key in the 'On' position, measure voltage at the ignition switch. Expected: 12-14 volts. If not, replace ignition switch.
- 22. Inspect wiring and connectors between the ignition switch and BCM for damage or corrosion. Repair as necessary. If damaged, this could cause a voltage drop.
- 33. With the ignition on, measure the voltage at the BCM connector. If voltage is present (10-14 volts) but the code persists, replace the BCM.
Common causes
- Faulty ignition switch
- Damaged wiring or connectors to the ignition system
- Defective Body Control Module
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, due to potential issues with lighting and other safety systems, avoid driving until repairs are made.
Will this code come back after clearing it?
If the underlying issue isn't fixed, yes, the code will reappear.
Why does this code relate to the ignition switch?
The BCM relies on the ignition switch signal to control various systems. If it doesn’t see the signal, it assumes the vehicle is off.
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