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U0073 on Hyundai Sonata

Control Module Communication Bus A Off

Factory diagnostic protocol and troubleshooting wire for fault code U0073 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
Critical urgency level
Est. Repair Cost
$150 - $850 (DIY: $40 - $200)
Parts & Labor DIY
Check U0073 On Another Hyundai Model:
Diagnose U0073 on Specific Sonata Model Year:

1. Symptoms of U0073 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 U0073, drivers commonly observe:

StabiliTrak / Traction / ABS / Engine warning lights lit on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Transmission shifting harshly or refusing to shift out of 2nd gear on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
No communication with TCM, ABS, or BCM on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Engine may refuse to crank 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%
Loose or corroded ground connection on transmission or frame (Hyundai OEM Part)
25%
Faulty Transmission Control Module (TCM) or ABS module pulling bus down (Hyundai OEM Part)
12%
Poor connection at large body-to-chassis pass-through harness connector (Hyundai OEM Part)
8%
Aftermarket accessory (remote starter, GPS tracker, cheap OBD scanner) broadcasting invalid data (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
Unplug All Aftermarket OBD-II Devices

Remove any aftermarket insurance dongles, GPS trackers, or scan tools plugged into the DLC port. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: None
02
Inspect Frame and Transmission Ground Straps

Inspect braided ground straps on engine and transmission. Clean all contact surfaces to bare metal. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Wire Brush, Sockets
03
Perform Full Vehicle Network Topology Scan

Scan all modules on vehicle. Note which modules are online and which are offline to pinpoint the break in the network daisy-chain. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Full-System OBD-II Diagnostic Scanner
04
Check Terminating Resistance (60 Ohms)

Verify 60 ohms across Pins 6 and 14 with battery disconnected. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Multimeter
05
Clear All System DTCs & Road Test

Clear DTCs from all modules and road test to verify error-free network transmission. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Scan Tool
Recommended Parts & Testing Tools

Equipment for Diagnosing Hyundai Sonata (U0073)

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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
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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 U0073 FAQs

What causes code U0073 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)), U0073 is most frequently caused by Loose or corroded ground connection on transmission or frame or Faulty Transmission Control Module (TCM) or ABS module pulling bus down.

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 U0073?

No. Bus is shut down due to excessive transmission errors, leaving vehicle in unpredictable limp mode. Given that U0073 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.