P0354 on Toyota Grand Highlander
Factory diagnostic protocol and troubleshooting wire for fault code P0354 specifically for the Toyota Grand Highlander (2024–2026, 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD).
1. Symptoms of P0354 on Toyota Grand Highlander
When the Engine Control Module (ECM/PCM) on your Toyota Grand Highlander (2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD) logs fault code P0354, drivers commonly observe:
2. Most Likely Causes on Toyota Grand Highlander
Historical warranty claims and technical repair bulletins for Toyota Grand Highlander point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Toyota Grand Highlander
Swap Coil 4 to Cylinder 1. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Install new OEM coil pack. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Clear memory and road test. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Equipment for Diagnosing Toyota Grand Highlander (P0354)
Direct-Fit Laser Iridium Spark Plugs (Set of 4/6)
Pre-gapped iridium spark plugs engineered to restore smooth combustion on Toyota Grand Highlander.
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 Grand Highlander
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota Grand Highlander:
4. Toyota Grand Highlander P0354 FAQs
What causes code P0354 to trigger on a Toyota Grand Highlander?
On the Toyota Grand Highlander (2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD), P0354 is most frequently caused by Dead Cylinder 4 ignition coil or Wiring damage.
Where is the OBD-II port located on my Toyota Grand Highlander?
On the Toyota Grand Highlander, the 16-pin DLC diagnostic connector is located Driver side lower knee panel above dead pedal. 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 Grand Highlander with code P0354?
No. Cylinder 4 ignition coil has failed. Given that P0354 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.

