C0604 code meaning
Active Air Dam Control Circuit Performance
Chassis system Generic code C06xx codes Check engine light
What C0604 means
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.
C0604 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0604
- 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
Common causes of C0604
- Most 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
- Less likelyAir dam lip rubbing on the front fascia
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Active air dam actuatorActive air dam modulePowertrain control module
What each part of C0604 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 04 | The exact fault in that area. |
What to do next
- Note C0604 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C0604
What does C0604 mean?
C0604 means "Active Air Dam Control Circuit Performance". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with C0604?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will C0604 fail an emissions test?
Yes, it can. C0604 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is C0604 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2.5 hours of work. This is a job for a workshop.
Will C0604 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.