B2545:04 Code - Backup Lamps Circuit Open

The code B2545:04 indicates an open circuit in the backup lamps, meaning the vehicle’s reverse lights are not functioning due to a broken or disconnected circuit.

The most common symptom is that the reverse lights will not illuminate when the vehicle is in reverse gear.

Common causes include a damaged or disconnected wiring harness, blown fuse, faulty reverse light bulb, malfunctioning reverse light switch, or a defective control module.

Start by checking the reverse light bulbs, fuses, and wiring for damage or disconnection. Use a multimeter to test for continuity in the circuit and inspect the reverse light switch.

Yes, a burned-out or faulty reverse light bulb can cause an open circuit, leading to this code being triggered.

Repairs may include replacing a faulty bulb, repairing damaged wiring, replacing a blown fuse, or replacing the reverse light switch if it’s defective.

While the car may still drive normally, it’s unsafe because other drivers won’t be able to see your reverse lights, increasing the risk of accidents when reversing.

Repair costs vary depending on the issue. Replacing a bulb or fuse is inexpensive, while fixing wiring or replacing the reverse light switch could be more costly, typically ranging from $50 to $300.

Yes, though it’s less common, a malfunctioning control module might fail to send the necessary signals to the backup lamps, causing the code.

Clearing the code may temporarily remove it, but unless the underlying issue is resolved, the code will likely return.