P0351 on Toyota 4Runner
Factory diagnostic protocol and troubleshooting wire for fault code P0351 specifically for the Toyota 4Runner (2020–2026, 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl).
1. Symptoms of P0351 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 P0351, drivers commonly observe:
2. Most Likely Causes on Toyota 4Runner
Historical warranty claims and technical repair bulletins for Toyota 4Runner point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Toyota 4Runner
Identify Cylinder 1 ignition coil pack mounted on the valve cover. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Swap Coil 1 with Coil 2. Clear codes and restart engine. If code switches to P0352 (Coil B), the ignition coil is 100% defective. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Check for 12V battery power, chassis ground, and 5V trigger pulse from the PCM on the 3-pin / 4-pin harness plug. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Install a new OEM ignition coil (e.g. Denso, Motorcraft, Delphi) and replace the spark plug on Cylinder 1. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Clear DTCs and verify smooth acceleration under load. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Equipment for Diagnosing Toyota 4Runner (P0351)
Direct-Fit Laser Iridium Spark Plugs (Set of 4/6)
Pre-gapped iridium spark plugs engineered to restore smooth combustion on Toyota 4Runner.
Magnetic Swivel Spark Plug Socket Set
360-degree magnetic swivel socket prevents ceramic plug cracks inside deep engine spark wells.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on Toyota 4Runner
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota 4Runner:
4. Toyota 4Runner P0351 FAQs
What causes code P0351 to trigger on a Toyota 4Runner?
On the Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl), P0351 is most frequently caused by Failed ignition coil pack on Cylinder 1 (Coil A) or Broken or melted wiring harness to ignition coil 1.
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 P0351?
No. Cylinder 1 ignition coil has failed completely, causing an active misfire and dumping unburned fuel into the catalytic converter. Given that P0351 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.

