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U0104 on Hyundai Sonata

Lost Communication with Cruise Control Module

Factory diagnostic protocol and troubleshooting wire for fault code U0104 specifically for the Hyundai Sonata (2020–2026, 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)).

Verified OEM Telemetry & Field Repair Tree
Hyundai Sonata2020–2026
Hyundai Sonata
Sedan2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Sonata SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
Low urgency level
Est. Repair Cost
$100 - $450 (DIY: $0 - $150)
Parts & Labor DIY
Check U0104 On Another Hyundai Model:
Diagnose U0104 on Specific Sonata Model Year:

1. Symptoms of U0104 on Hyundai Sonata

When the Engine Control Module (ECM/PCM) on your Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)) logs fault code U0104, drivers commonly observe:

Adaptive Cruise Control (ACC) disabled on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Pre-Collision System warning light on on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Check Engine Light on on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Hyundai Sonata OBD-II Port Location
The 16-pin diagnostic connector is located Under driver side steering column. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Hyundai Sonata

Historical warranty claims and technical repair bulletins for Hyundai Sonata point to the following failure distribution:

55%
Blocked or dirty front radar sensor in grille/bumper (Hyundai OEM Part)
25%
Blown radar module fuse (Hyundai OEM Part)
12%
Faulty radar cruise control module (Hyundai OEM Part)
8%
Misaligned radar sensor following minor bumper bump (Hyundai OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Hyundai Sonata.

3. Step-by-Step DIY Repair Guide for Hyundai Sonata

01
Clean Front Radar Sensor in Grille

Clean snow, ice, mud, or dead bugs off front radar emblem. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Microfiber Towel
02
Check ACC / Radar Fuse

Verify power feed to radar sensor. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Test Light
03
Perform Radar Aiming Calibration

Execute optical/radar alignment procedure if bumper was removed. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Calibration Target, Scan Tool
04
Clear Trouble Codes

Clear DTCs and test cruise on highway. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Hyundai Sonata (U0104)

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Direct-Fit Replacement Part

Hyundai Sonata OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Hyundai Sonata.

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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Hyundai SonataVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Hyundai Sonata

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Hyundai Sonata:

4. Hyundai Sonata U0104 FAQs

What causes code U0104 to trigger on a Hyundai Sonata?

On the Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)), U0104 is most frequently caused by Blocked or dirty front radar sensor in grille/bumper or Blown radar module fuse.

Where is the OBD-II port located on my Hyundai Sonata?

On the Hyundai Sonata, the 16-pin DLC diagnostic connector is located Under driver side steering column. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Hyundai Sonata with code U0104?

Yes. Normal driving is unaffected, but Adaptive Cruise Control will not engage. Given that U0104 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.