Code
B2949
HYUNDAI
B — Body
Radio Antenna Connection & Receive Quality
Views:
UK: 14
EN: 12
RU: 11
AI status
Completed
Completed
100%
Causes
- Loose, corroded or disconnected antenna/coax connector
- Damaged antenna mast or broken antenna element
- Open or shorted coaxial cable (feed/ground)
- Failed antenna amplifier (active antenna)
- Blown fuse or loss of power to antenna amplifier
- Poor ground or wiring damage (chafing, water intrusion)
Symptoms
- Weak or no AM/FM reception
- Intermittent station reception, dropouts or increased static
- One band (AM or FM) not working while the other does
- On-screen radio/antenna error or poor reception message (if equipped)
- Noise increases or changes with engine speed or vehicle motion
- Antenna mast not extending/retracting (on power mast systems)
What to check
- Scan for stored radio/BCM/antenna codes and freeze frame data; record or clear codes and retest
- Visually inspect the antenna mast, base and coax connector for corrosion, damage or water intrusion
- Check antenna mast operation (if power mast): verify motor/power and ground when radio is turned on
- Inspect wiring harness and connector between antenna and radio/amplifier for damage or loose pins
- Verify fuses and relays for radio/antenna amplifier circuits
- Wiggle test coax and connectors while monitoring reception or DTC status for intermittent faults
Signal parameters
- FM broadcast band: 88–108 MHz (RF level for good reception commonly >20–40 dBµV depending on area)
- AM broadcast band: ~530–1710 kHz (AM susceptibility varies by antenna and location)
- Antenna amplifier supply voltage: typically battery voltage (~11–14 V) or amplifier bias (check vehicle spec)
- Coax impedance: nominally 50 Ω (check for open/short/low insulation resistance)
- Continuity: center conductor continuity between radio antenna input and antenna base (near 0 Ω if short, open if high Ω)
- Shield/ground: continuity between coax shield and vehicle ground
Diagnostic algorithm
- Read and record all stored codes with a compatible scan tool. Note freeze frame and any related U-codes.
- Visually inspect antenna mast, base, harness and connectors for corrosion, breaks, or water intrusion. Repair obvious damage.
- Verify fuses/relays for radio and antenna amplifier circuits; replace if blown and retest.
- With radio ON, measure supply voltage to antenna amplifier or power mast: verify expected bias/power (refer to service data).
- Check ground at antenna and radio chassis: ensure clean, secure ground connection.
- Use a multimeter to check continuity of the coax center conductor and shield between the radio input and antenna base. Replace coax if open or shorted.
- If equipped with an active amplifier, disconnect amplifier and bench-test or substitute known-good amplifier to confirm fault.
- Wiggle connectors and coax while monitoring reception and DTCs to find intermittent faults. Repair/replace faulty connectors or harness sections.
- Test radio reception with a known-good external antenna or swap in a known-good head unit to isolate radio vs. antenna/amplifier.
- After repairs, clear codes and road-test to confirm fault does not return. If code persists, refer to manufacturer service manual for module-level diagnostics and wiring diagrams.
Likely causes
- Corroded or loose antenna/coax connector at antenna base
- Failed antenna amplifier or amplifier power feed (most common on vehicles with powered/active antennas)
- Broken or cut coaxial cable between antenna and radio
- Faulty ground at antenna or radio chassis ground
- Intermittent connection caused by water ingress at antenna base
Fault status
Status
Radio antenna connection & receive quality — detected poor or interrupted antenna signal path, open/short in antenna circuit, or failed antenna amplifier affecting radio reception.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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