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P0443LexusLexus NX HubAll Lexus P0443Medium Severity

P0443 on Lexus NX

EVAP System Purge Control Valve Circuit Malfunction

Factory diagnostic protocol and troubleshooting wire for fault code P0443 specifically for the Lexus NX (2022–2026, 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP)).

Verified OEM Telemetry & Field Repair Tree
Lexus NX2022–2026
Lexus NX
SUV2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
NX SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. Repair Cost
$90 - $250 (DIY: $25 - $70)
Parts & Labor DIY
Check P0443 On Another Lexus Model:
Diagnose P0443 on Specific NX Model Year:

1. Symptoms of P0443 on Lexus NX

When the Engine Control Module (ECM/PCM) on your Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP)) logs fault code P0443, drivers commonly observe:

Check Engine Light on on Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP))
Engine hard to start immediately after pumping gas at the gas station on Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP))
Rough or fluctuating engine idle on Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP))
Slight fuel odor under hood on Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP))
Lexus NX OBD-II Port Location
The 16-pin diagnostic connector is located Under driver dash near footwell illumination lamp. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Lexus NX

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

55%
Failed EVAP purge solenoid coil (open or shorted internally) (Lexus OEM Part)
25%
Broken or frayed wiring harness to purge valve connector (Lexus OEM Part)
12%
Blown EVAP fuse in fuse block (Lexus OEM Part)
8%
Corroded pins inside electrical plug (Lexus OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Lexus NX.

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

01
Locate EVAP Purge Solenoid Under Hood

Find the purge valve mounted on the intake manifold with one vacuum line leading to the intake and one to the charcoal canister. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).

Required Tool: Flashlight
02
Test Purge Valve Solenoid Resistance

Unplug 2-pin connector and measure resistance across terminals with multimeter. Typical spec is 14–30 ohms. If open (OL) or shorted (0 ohms), solenoid is dead. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).

Required Tool: Digital Multimeter
03
Test Vacuum Sealing

Remove purge valve and blow into it. A healthy de-energized purge valve should be 100% sealed. If air passes through, the internal seal is stuck open. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).

Required Tool: Hand Vacuum Pump
04
Replace EVAP Purge Valve

Disconnect quick-release vapor lines, unbolt mounting bracket, snap new OEM purge valve into place, and reconnect electrical plug. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).

Required Tool: 10mm Socket, Pliers
05
Clear Codes

Clear DTCs with scanner and verify EVAP monitor completes. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).

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

Equipment for Diagnosing Lexus NX (P0443)

Prime Fast Delivery & Verified Fitment
EVAP Seal Replacement

OEM Tethered Fuel Gas Cap with O-Ring

4.7 / 5.0 (Direct Fit)

Tight-sealing factory fuel cap resolves common EVAP small/large leak codes without workshop visits.

$17 – $26 Prime
Check Fitment on Amazon
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 Lexus NXVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Lexus NX

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

4. Lexus NX P0443 FAQs

What causes code P0443 to trigger on a Lexus NX?

On the Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP)), P0443 is most frequently caused by Failed EVAP purge solenoid coil (open or shorted internally) or Broken or frayed wiring harness to purge valve connector.

Where is the OBD-II port located on my Lexus NX?

On the Lexus NX, the 16-pin DLC diagnostic connector is located Under driver dash near footwell illumination lamp. 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 NX with code P0443?

Yes. Safe to drive, but engine may experience hard starting after refueling at gas station. Given that P0443 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.