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OBD-II Diagnostic Trouble Code
B16AC

Driver side door handle antenna failure

B
Body
comfort / safety
1
Mfr
manufacturer code
6
Body subsystem
AC
Driver side door handle antenna failure
Severity · general guide
Varies
Body/safety — depends on system
Code type
Kia
System
Body
Model
EV6
Years
2022
Quick answer

Kia B16AC indicates a failure in the driver side door handle antenna used for the Passive Entry (keyless entry) system — the BCM or Smart Entry Module cannot communicate with the LF (low-frequency) antenna embedded in the driver door handle.

What B16AC means

Kia's Smart Entry system uses a network of Low Frequency (LF) antennas positioned around the vehicle to detect the proximity of the smart key fob. The driver side door handle contains one such LF antenna, which transmits a wake-up signal to activate nearby smart keys. The Smart Entry Module (or BCM on integrated systems) continuously monitors the antenna circuit for proper impedance and communication response. B16AC is stored when the driver door handle antenna circuit shows a fault — either an open circuit (broken antenna wire or disconnected connector), a short circuit, or the antenna is not responding to the module's poll. This typically causes the driver door touch sensor (capacitive or button) to fail to unlock the vehicle via passive entry, while the physical remote button on the fob may still work if the RF path is unaffected.

Symptoms

  • Driver door passive entry (touch-to-unlock) not working while other passive entry zones may still function
  • B16AC stored in the Smart Entry or BCM fault log
  • Smart key fob RF button unlock continues to work normally (different system path)
  • Push-button start may still function if the cabin interior antennas can detect the fob
  • No warning lamp typically — B16AC is a comfort feature fault, not a safety fault

Common causes

  • Broken LF antenna wire inside the driver door handle — common after door panel removal/refitting or antenna damage from impact
  • Water ingress into the driver door handle antenna connector — Kia door handle connectors are exposed to weather and can corrode over time
  • Damaged or kinked antenna harness in the door hinge area — the harness running from the door body to the door panel flexes repeatedly and can break
  • Failed Smart Entry Module internal driver for the driver antenna circuit
  • Aftermarket door handle replacement where the antenna was not transferred or connected correctly

Diagnostic approach

  1. Access the driver door handle antenna connector and inspect for damage — Remove the driver door inner trim panel to access the LF antenna wiring. The antenna itself is typically clipped into the inner face of the door handle assembly, with a 2-pin connector. Inspect the connector for corrosion, pushed-back pins, or broken solder joints on the antenna element. Clean and re-seat the connector if any contamination is found.
  2. Measure antenna circuit resistance at the Smart Entry Module connector — Using the Kia wiring diagram for the specific model, identify the driver door handle antenna circuit pins at the Smart Entry Module connector. Disconnect the module and measure resistance across the antenna pins. A properly wound LF antenna typically shows 3-10 ohms. Open circuit (OL/infinite resistance) confirms a broken antenna wire. Very low resistance (near zero) confirms a short circuit.
  3. Inspect and test the door hinge harness with the door cycling — Have an assistant open and close the driver door slowly while you monitor antenna circuit continuity with a multimeter. Intermittent continuity loss as the door moves confirms a harness break at the hinge. The flex section of the hinge harness is the most common failure point on Sportage QL, Ceed CD, and Stinger CK.

Make & model notes

Kia: Sportage QL (2016-2021): B16AC on this model is frequently caused by the door hinge harness chafing at the lower hinge entry point. Inspect carefully — the fault can be intermittent and may not be present when the door is open for inspection. Cycle the door and watch for continuity changes.

Kia: Stinger CK (2017-2022): the Stinger door handle antenna is integrated into the exterior door handle assembly. Replacement requires a full handle assembly replacement — the antenna cannot be serviced separately. Verify the fault is in the antenna wiring before ordering a new handle assembly.

FAQ

Can I still unlock my Kia if B16AC is present?

Yes. B16AC only affects the passive entry (touch-to-unlock) function at the driver door handle. Your smart key fob RF button will still unlock the car normally, and the push-button start will still work as long as the fob is inside the cabin. Only the hands-free touch-unlock at the driver door is affected.

Is B16AC likely to be covered under warranty?

If the vehicle is within the factory new vehicle warranty period (5 years/100,000 km on most Kia markets), B16AC caused by a component failure is typically covered. Damage caused by aftermarket modifications, water ingress through a door seal that was not maintained, or accident damage is usually excluded.

How expensive is it to repair B16AC?

If the fault is a corroded connector or broken harness wire, repair cost is minimal — a few hours of labour to access and repair the wiring. If the full door handle assembly needs replacement (as on Stinger CK), parts cost can range from 80-200 EUR plus labour depending on market and trim level.