Right Blend Door Travel Too Small (ATC)

What B10AD means

On a dual-zone (ATC) 300C, Charger or Magnum, each side's blend-air (temperature) door is driven by a 12-volt actuator, and the A/C-Heater control learns each door's travel by sweeping it stop-to-stop and counting pulses. B10AD sets when the RIGHT door's measured span is SMALLER than expected — something is stopping the door short of its full travel. Because the door can't swing all the way between the heat and cool positions, the right side of the cabin has a reduced temperature range and often can't get fully warm or fully cold. 'Right' is the physical right of the vehicle (the driver's side on a right-hand-drive car).

Symptoms

• The right side of the cabin can't reach full heat or full cold — limited range
• That side feels 'stuck in the middle' or biased warm or cool
• Left side of the dual-zone system still covers its full range
• B10AD stored in the A/C-Heater module

Common causes

• Something physically obstructing or jamming the right blend door (debris, a dislodged foam seal, a foreign object in the housing)
• Bent, broken, or binding door linkage that limits how far the door can travel
• A seizing or weak right blend-door actuator that stalls before the door reaches its stop
• Faulty A/C-Heater control (module)

Severity & driving advice

Severity: Low — Comfort fault only — safe to drive; a scan tool that reaches the A/C-Heater module is needed to diagnose it.

Can I drive? Safe to drive; climate-comfort fault only.

Diagnostic approach

1. Read the HVAC codes and repair circuit faults first — Clear any active Control Circuit / Performance or Control Circuit Open codes for the right door before diagnosing B10AD.
2. Check the door for obstruction and binding — Rotate the right blend door stop-to-stop by hand — it should sweep about 190 degrees freely. Look for debris, a jammed seal, or bent linkage that stops it short.
3. Clear the obstruction or repair the linkage — Remove any foreign object and free or repair the binding linkage, then re-run the calibration.
4. If the door moves freely but the code returns, replace the actuator — A weak or seizing actuator can stall before the stop. Replace the right blend-door actuator and calibrate; if it still fails, suspect the control module.

Estimated repair costs

Typical US repair costs (parts & labour) for the faults behind B10AD. These are national-average estimates, not a quote— your actual price varies by region, shop labour rate, and your vehicle’s make, model and year. Figures reviewed 2026.

Make & model notes

Chrysler / Dodge / Jeep: B10AD is the dual-zone (ATC) RIGHT blend-door 'travel too small' code on LX-platform cars (300 / 300C, Charger, Magnum) and related FCA models — the counterpart to B10AE. Where B10AE is over-travel (often stuck full hot), B10AD is under-travel: the door can't complete its sweep, so that side can't reach the temperature extremes. Check for something jamming the door before replacing parts. The actuator is a three-screw, one-connector bolt-on behind the lower-dash trim; calibrate after any actuator or control-head change.

FAQ