Rear Window Defogger Control Circuit Fault
There’s an issue with the rear window defogger system control circuit.
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 rear window defogger needs a working control circuit to function. If B1416 is set, it means the computer detected a problem in the electrical path that turns the defogger on or off.
What the computer is actually seeing
The powertrain control module (PCM) monitors the rear window defogger control circuit for correct voltage and continuity. It expects a certain resistance in the circuit when the defogger switch is activated.
What a healthy reading looks like
Expected voltage on the control circuit when activated is around 12V; when off, it should be near 0V.
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 wiring and connectors for damage or corrosion in the rear window defogger circuit. Decision Point: Are all connections intact? If not, repair or replace as necessary.
- 22. Test the voltage at the rear window defogger switch when activated. Expected: 12V. Decision Point: Is voltage present? If not, check the power supply and continuity in the circuit.
- 33. Check the operation of the rear window defogger switch itself using a multimeter. Decision Point: Is the switch functioning? If not, replace the switch.
- 44. If the problem persists, test the control relay for proper operation. Decision Point: Does the relay click and provide voltage to the defogger load? If not, replace the relay.
Common causes
- Damaged wiring in the rear window defogger circuit
- Faulty rear window defogger switch
- Defective power relay for the defogger
- Corroded connectors or terminals
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
Yes, it's safe to drive, but the rear window defogger won't work until the issue is resolved.
Will this code come back after being cleared?
If the underlying issue isn't fixed, yes, the code will likely return.
Why does this code appear with other codes?
It may indicate a larger issue with the electrical system affecting multiple components.
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