C0019 indicates a malfunction in the left rear outlet (or left rear brake light) control circuit. The powertrain control module has detected an abnormal voltage or resistance condition in that circuit.
A filament that has failed open or a bulb that has shorted to ground can cause abnormal voltage readings.
Moisture, rust, or physical damage can increase resistance or create a short in the circuit.
The relay that switches power to the left rear outlet may be stuck open or shorted.
A poor ground connection can cause the control module to see an out‑of‑range voltage.
Rarely, a corrupted PCM memory can misinterpret a good circuit as faulty; re‑flashing or replacement is a last‑resort fix.
In most cases no. The PCM is rarely at fault; the problem is almost always a bulb, wiring, connector, or relay issue. Replace the PCM only after all other components have been verified functional.
A short to ground or a stuck relay can supply constant voltage to the lamp, causing it to remain illuminated even when the brake pedal is not pressed.
Yes. A partially failed bulb can create abnormal resistance that the PCM interprets as a fault, triggering C0019 even though the light still lights dimly.
The code may clear temporarily, but if the underlying fault remains, the PCM will set the code again on the next drive cycle.