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C0601 — Active Air Dam Control Circuitopen

Generic OBD-II · all makesChassis

C0601 indicates that the vehicle’s control module has detected an open circuit in the active air dam control system. The active air dam is a movable front‑panel that deploys at higher speeds to improve aerodynamics; an open circuit prevents the module from commanding the dam to move.

Symptoms

What causes it — most likely first

1. Damaged wiring harness or connector

Corrosion, chafing, or loose pins in the air dam circuit wiring can create an open circuit that the module detects.

2. Failed air dam actuator motor or position sensor

If the actuator motor burns out or its internal position sensor fails, the module cannot drive the dam and logs an open circuit.

3. Blown fuse or faulty relay

The fuse or relay supplying power to the active air dam circuit may be open, preventing voltage from reaching the actuator.

4. Mechanical obstruction or jam

Debris, ice, or a broken linkage can prevent the dam from moving, causing the module to interpret the lack of movement as an electrical open.

5. Software glitch or outdated calibration

A body control module software error may misread circuit status; updating or reflashing can resolve false positives.

6. Control module (BCM/PCM/ECM) failure

Only considered after all wiring, connectors, actuator, fuses, and mechanical checks pass; module failure is rare for this code.

How it's diagnosed

  1. Read and record C0601 and any related codes with a scan tool; note freeze‑frame data.
  2. Visually inspect the active air dam wiring harness and connectors for damage, corrosion, or loose connections; repair as needed.
  3. Test continuity and resistance of the control circuit from the module to the actuator according to service specifications.
  4. Check the fuse and relay for the active air dam system; replace if open or faulty.
  5. Command the air dam to deploy/retract via the scan tool; listen for motor operation and measure voltage at the actuator during the command.
  6. If voltage is present but the actuator does not move, replace the actuator/motor assembly; if voltage is absent, trace the wiring further; if all electrical tests pass, consider a module software update or module replacement as a last resort.

Code facts & related codes

SystemChassis
StandardizationSAE generic — identical on every make

Frequently asked

Do I need to replace the PCM/ECM to fix C0601?

No. The PCM/ECM is rarely the cause of C0601. Most cases stem from wiring, connectors, the air dam actuator, or a blown fuse. Only consider module replacement after all wiring and actuator tests have passed.

Can a blown fuse cause C0601?

Yes. If the fuse supplying power to the active air dam circuit is open, the module will see an open circuit and set the code.

Will driving with the air dam stuck affect safety?

The air dam primarily influences aerodynamics and fuel efficiency. A stuck dam usually does not impair braking or steering, but it may reduce fuel economy and increase wind noise.

Should I clear the code and see if it returns?

Clearing the code without repairing the underlying issue will likely cause it to return once the module again detects the open circuit. Perform the diagnostic steps first.