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U0073LexusLexus RX HubAll Lexus U0073Critical Severity

U0073 on Lexus RX

Control Module Communication Bus A Off

Factory diagnostic protocol and troubleshooting wire for fault code U0073 specifically for the Lexus RX (2020–2026, 2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP)).

Verified OEM Telemetry & Field Repair Tree
Lexus RX2020–2026
Lexus RX
SUV2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
RX 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 Lexus Model:
Diagnose U0073 on Specific RX Model Year:

1. Symptoms of U0073 on Lexus RX

When the Engine Control Module (ECM/PCM) on your Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP)) logs fault code U0073, drivers commonly observe:

StabiliTrak / Traction / ABS / Engine warning lights lit on Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP))
Transmission shifting harshly or refusing to shift out of 2nd gear on Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP))
No communication with TCM, ABS, or BCM on Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP))
Engine may refuse to crank on Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP))
Lexus RX OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell above brake pedal assembly. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Lexus RX

Historical warranty claims and technical repair bulletins for Lexus RX point to the following failure distribution:

55%
Loose or corroded ground connection on transmission or frame (Lexus OEM Part)
25%
Faulty Transmission Control Module (TCM) or ABS module pulling bus down (Lexus OEM Part)
12%
Poor connection at large body-to-chassis pass-through harness connector (Lexus OEM Part)
8%
Aftermarket accessory (remote starter, GPS tracker, cheap OBD scanner) broadcasting invalid data (Lexus OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Lexus RX.

3. Step-by-Step DIY Repair Guide for Lexus RX

01
Unplug All Aftermarket OBD-II Devices

Remove any aftermarket insurance dongles, GPS trackers, or scan tools plugged into the DLC port. on the Lexus RX equipped with 2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP).

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 Lexus RX equipped with 2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP).

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 Lexus RX equipped with 2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP).

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 Lexus RX equipped with 2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP).

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 Lexus RX equipped with 2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP).

Required Tool: Scan Tool
Recommended Parts & Testing Tools

Equipment for Diagnosing Lexus RX (U0073)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

Lexus RX OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Lexus RX.

$45 – $95 Prime
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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 Lexus RXVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Lexus RX

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Lexus RX:

4. Lexus RX U0073 FAQs

What causes code U0073 to trigger on a Lexus RX?

On the Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP)), 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 Lexus RX?

On the Lexus RX, the 16-pin DLC diagnostic connector is located Driver footwell above brake pedal assembly. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Lexus RX 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.