نصب لامپ LED به جای چراغ هشدار

An LED fitted where a filament bulb belongs, in a circuit the module monitors by measuring current. A filament draws enough current to be detected; an LED draws almost none, so the module concludes the bulb is missing and reports an open circuit.

The lamp works perfectly, which is what makes this confusing. The light illuminates, the driver sees nothing wrong, and the module insists the circuit is open — so the code appears to contradict the evidence. A warning lamp that visibly works with a circuit fault stored against it is this, and the vehicle's recent history usually explains it.

It can also cause the opposite problem, where a module drives the lamp with a small monitoring current that is enough to make an LED glow faintly when it should be off. Fit the specified bulb, or a load-compensating LED designed for a monitored circuit — and check any recent bulb changes before diagnosing the harness, since this is entirely self-inflicted and free to reverse.