A bulb failure warning for one or several taillight functions appears in the instrument cluster, but the taillights are operating normally. The warning only occurs at very low outside temperatures. DTC entries are logged in the comfort system central control module. The transistor in the taillight is a component of the bulb failure monitor. The transistor is out of tolerance, which causes the bulb failure monitor to not see enough current consumption when outside temperatures are very low. This causes a false lamp failure warning.
