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P2004 on Toyota 4Runner

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

Factory diagnostic protocol and troubleshooting wire for fault code P2004 specifically for the Toyota 4Runner (2020–2026, 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl).

Verified OEM Telemetry & Field Repair Tree
Toyota 4Runner2020–2026
Toyota 4Runner
SUV4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
4Runner 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 Toyota Model:
Diagnose P2004 on Specific 4Runner Model Year:

1. Symptoms of P2004 on Toyota 4Runner

When the Engine Control Module (ECM/PCM) on your Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl) logs fault code P2004, drivers commonly observe:

Check Engine Light on on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Sluggish low-RPM acceleration and low-end torque loss on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Engine runs fine at high highway RPMs (3,500+ RPM) on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Slightly rough idle or minor intake whistling noise on Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl)
Toyota 4Runner OBD-II Port Location
The 16-pin diagnostic connector is located Lower dashboard near parking brake mechanism. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Toyota 4Runner

Historical warranty claims and technical repair bulletins for Toyota 4Runner point to the following failure distribution:

55%
Carbon buildup binding the intake manifold swirl flap runner plates (Toyota OEM Part)
25%
Broken plastic IMRC actuator linkage rod or vacuum diaphragm (Toyota OEM Part)
12%
Faulty electronic IMRC runner control motor / solenoid (Toyota OEM Part)
8%
Cracked vacuum line to IMRC actuator (Toyota OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Toyota 4Runner.

3. Step-by-Step DIY Repair Guide for Toyota 4Runner

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 Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

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 Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

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 Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

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 Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

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 Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.

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

Equipment for Diagnosing Toyota 4Runner (P2004)

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Toyota 4Runner OEM Replacement Sensor

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Direct-fit replacement assembly engineered to OEM tolerances for Toyota 4Runner.

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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.

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BlueDriver Bluetooth Pro OBDII Scan Tool

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

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Other Common Fault Codes on Toyota 4Runner

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota 4Runner:

4. Toyota 4Runner P2004 FAQs

What causes code P2004 to trigger on a Toyota 4Runner?

On the Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl), 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 Toyota 4Runner?

On the Toyota 4Runner, the 16-pin DLC diagnostic connector is located Lower dashboard near parking brake mechanism. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Toyota 4Runner 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.