Nissan Altima 2007 Fault Codes P1610, P1611, P0603, U1001 - Self-Activating AC and Headlights with Water Intrusion Suspected
My 2007 Nissan Altima has been exhibiting strange electrical behavior after a rainy day. After driving in the rain and parking, the AC fans started running on their own while the car was off. I immediately pressed the unlock button on the key fob to stop them, which worked temporarily. Later that evening, the headlights turned on by themselves. When I tried to start the vehicle, I noticed a wheel icon appear on the dashboard, which then disappeared. Since then, the car has not started and remains unresponsive. The onboard diagnostic system shows persistent error codes: P1610, P1611, P0603, and U1001. I suspect water intrusion into the ECM or wiring harness due to exposure during rain. A technician attempted replacing the ECM with a new unit, but the error codes remain unresolved and the vehicle still won't start.
Possible water intrusion into the Engine Control Module (ECM) or related wiring harness, especially after exposure to rain. This could cause intermittent electrical faults like self-activating AC and headlights.