C0602 is a chassis diagnostic code indicating the Active Air Dam control circuit is reading below the expected voltage threshold. The active air dam is a movable front spoiler that adjusts for optimal aerodynamic drag at different speeds. When the system detects a circuit low condition, it typically disables the air dam function and may illuminate a warning indicator.
The electric motor or actuator that moves the air dam has failed, causing an open or high-resistance circuit that reads as low voltage.
Short to ground or open circuit in the wiring between the control module and air dam actuator, often from road debris or corrosion.
The position sensor that tells the module the air dam location has failed, causing incorrect voltage readings on the control circuit.
Water intrusion or oxidation at the air dam connector can cause low voltage readings and intermittent codes.
A failed fuse or relay in the air dam power circuit can cause a permanent low voltage condition.
The module that commands the air dam has failed, though this is rare compared to upstream component failures.
No. The engine computer (PCM/ECM) is almost never the cause of C0602. This code relates to the chassis active air dam system, which is separate from the powertrain control module. Technicians sometimes replace the PCM unnecessarily when the actual fault is the actuator, wiring, or sensor.
Yes, the vehicle is drivable. The air dam may stay in one position, potentially slightly affecting fuel economy at highway speeds. The warning light may remain on.
No. This code indicates a hard fault in the circuit—either a failed component or wiring issue. It will not clear on its own and requires diagnosis.
Active air dam systems are used by multiple manufacturers. The code logic (C0602) follows the standard J1979/J2012 diagnostic format, though implementation varies by vehicle.