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P2004LexusLexus RX HubAll Lexus P2004Medium Severity

P2004 on Lexus RX

Intake Manifold Runner Control (IMRC) Stuck Open (Bank 1)

Factory diagnostic protocol and troubleshooting wire for fault code P2004 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
Drivable (Short Trip)
Medium urgency level
Est. Repair Cost
$150 - $600 (DIY: $40 - $180)
Parts & Labor DIY
Check P2004 On Another Lexus Model:
Diagnose P2004 on Specific RX Model Year:

1. Symptoms of P2004 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 P2004, drivers commonly observe:

Check Engine Light on on Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP))
Sluggish low-RPM acceleration and low-end torque loss on Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP))
Engine runs fine at high highway RPMs (3,500+ RPM) on Lexus RX (2.4L Turbo (RX 350 275HP) / 2.5L Hybrid / 2.4L Turbo Performance Hybrid (RX 500h 366HP))
Slightly rough idle or minor intake whistling noise 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%
Carbon buildup binding the intake manifold swirl flap runner plates (Lexus OEM Part)
25%
Broken plastic IMRC actuator linkage rod or vacuum diaphragm (Lexus OEM Part)
12%
Faulty electronic IMRC runner control motor / solenoid (Lexus OEM Part)
8%
Cracked vacuum line to IMRC actuator (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
Visually Inspect IMRC Actuator Linkage

Check the mechanical plastic linkage arms at the end of the intake manifold. Verify arms are not popped off or broken. 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: Flashlight, Mirror
02
Test Runner Flap Movement Manually

Move the runner lever by hand. It should spring back smoothly without binding or gritty resistance. 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
03
Test IMRC Solenoid / Actuator Motor

Command IMRC open and closed with bi-directional scan tool or check vacuum supply to diaphragm. 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: OBD-II Bi-Directional Scanner or Vacuum Gauge
04
Clean Intake Manifold Carbon or Replace Actuator

Replace the broken linkage/actuator motor or remove manifold to clean heavy carbon deposits around the butterfly flaps. 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: Socket Set, Carburetor Cleaner, Gasket Set
05
Clear DTCs and Verify Runner Operation

Clear trouble codes and confirm low-end acceleration is restored. 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: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Lexus RX (P2004)

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 P2004 FAQs

What causes code P2004 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)), P2004 is most frequently caused by Carbon buildup binding the intake manifold swirl flap runner plates or Broken plastic IMRC actuator linkage rod or vacuum diaphragm.

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 P2004?

Yes. Low-end engine torque will feel sluggish, but vehicle is drivable. Given that P2004 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.