C0604Active Air Dam Control Circuit Performance
- Generic OBD-II code · Chassis
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- C0604 is the air dam code that makers really publish: the panel does not reach or hold its commanded position even though the circuit itself looks sound. Ford stores C0604:00 in the PCM of 2021–2023 F-150s, often with a cluster warning that the air dam system has failed; its fixes are new left and right actuators for an actuator firmware issue (SSM 51718), a PCM reflash (TSB 24-2404, later 25-2155 and 25-2236) and, on 2021–2025 trucks, new bolts where the actuator-to-dam bolts broke (SSM 54705). Stellantis ties C0604 to water in the connector and to fascia contact causing a clunk at 15–35 mph, and on a 2025 Ram 1500 to impact damage, with the MIL lit. GM's patent splits such faults into sensor, actuator and panel cases.
- What you may notice
- Active Air Dam System Fault See Manual message
- Air dam hangs down or does not retract
- Clunk from the front end when driving at moderate speed or decelerating
- Check engine lamp on some Ram trucks
- Likely causes
- LikelyActuator firmware or PCM software level with known false or real faults (Ford F-150)
- PossibleBroken bolts between actuator and air dam, panel hangs
- PossibleAir dam bent, cracked or jammed after ground contact or debris
- PossibleWater or corrosion in the actuator connector
- RareAir dam lip rubbing on the front fascia
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.