لامپ‌های دنده عقب خراب

The reversing lamp bulbs blown, on a circuit the module monitors. It detects the lamps by the current they draw, so bulbs that have failed read as an open circuit — the code names the circuit rather than the bulbs.

Both failing together is commoner than it sounds, since they are the same age and used equally. Check the bulbs and their holders first: corroded holders are frequent on a rear cluster exposed to water. An LED conversion produces the identical code by drawing almost no current, which is a common and entirely self-inflicted cause. A reversing camera or parking system that has also stopped working points at the switch or the supply instead, since those share it.