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DTC codes / C06xx · Brakes, steering and suspension / C0602

C0602Active Air Dam Control Circuit Low

C0602 indicates that the active air dam control module has detected an abnormally low voltage or current on the circuit that powers or controls the movable front air dam. The computer expects a certain electrical load when commanding the air dam actuator, but the feedback signal falls below the acceptable threshold, signaling an open circuit, short to ground, or faulty actuator.

SystemChassis
Code typeGeneric (all makes)
SeverityLow
Fix difficultyIntermediate
AreaBrakes, steering and suspension

Symptoms you may notice

  • Illumination of the check engine light or a specific service message for the active air dam system.
  • The active air dam may remain in the deployed (down) position at all times, reducing ground clearance.
  • The air dam may stay retracted (up) and fail to deploy at highway speeds, hurting fuel economy.
  • A warning chime or message on the driver information center stating the air dam is unavailable.
  • Often no symptoms besides the warning light, as the vehicle remains driveable with the air dam stuck in one position.

Common causes, most likely first

  1. Damaged or disconnected wiring harness at the air dam actuator, often due to road debris or flexing.
  2. Corroded or loose electrical connector at the air dam motor or control module.
  3. Failed air dam actuator motor, which may have an open winding or internal short.
  4. Blown fuse or faulty relay in the air dam control circuit.
  5. Water intrusion into the actuator or connector causing a short to ground.
  6. Faulty active air dam control module, though this is less common than wiring or actuator issues.

How to diagnose and fix it

  1. Inspect the air dam actuator and its wiring for visible damage, corrosion, or loose connectors, and repair as needed.
  2. Check the fuse and relay for the active air dam circuit and replace any that are blown or faulty.
  3. Disconnect the actuator connector and measure resistance across the motor terminals to check for an open or shorted winding.
  4. With the connector disconnected, check for voltage and ground signals at the harness side while commanding the air dam with a scan tool.
  5. Perform a wiggle test on the harness while monitoring live data to identify intermittent opens or shorts.
  6. If the actuator fails electrical tests, replace the air dam actuator assembly and clear the code.
  7. After repairs, clear the code and verify the air dam operates through its full range with a bidirectional scan tool.

What the low circuit code really means

  • A low circuit code often results from a simple unplugged connector after front-end bodywork or bumper removal, not a failed actuator.
  • The active air dam may share a ground with other body components, so a bad ground elsewhere can set this code without any air dam fault.
  • Some vehicles set C0602 when the air dam is physically jammed by snow or ice, causing the motor to draw low current as it stalls.
  • A scan tool that can command the air dam is essential; static resistance checks alone may miss an intermittent fault that only appears when the motor is powered.
  • Do not overlook the possibility of a chafed wire inside the loom where it bends near the actuator, as this is a common hidden cause.

Can I keep driving with C0602?

You can generally continue driving with this code because the air dam is an efficiency device and does not affect safety or engine operation. Avoid high-speed driving if the air dam is stuck down, as it may reduce ground clearance and increase the risk of damage over speed bumps or steep driveways.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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